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gerrit-public.fairphone.software / platform / external / ImageMagick / d5a730e3325bc42c94f8b313c66d49f9fb0baa75 / . / magick / quantize.c
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/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% QQQ U U AAA N N TTTTT IIIII ZZZZZ EEEEE %
% Q Q U U A A NN N T I ZZ E %
% Q Q U U AAAAA N N N T I ZZZ EEEEE %
% Q QQ U U A A N NN T I ZZ E %
% QQQQ UUU A A N N T IIIII ZZZZZ EEEEE %
% %
% %
% MagickCore Methods to Reduce the Number of Unique Colors in an Image %
% %
% Software Design %
% John Cristy %
% July 1992 %
% %
% %
% Copyright 1999-2009 ImageMagick Studio LLC, a non-profit organization %
% dedicated to making software imaging solutions freely available. %
% %
% You may not use this file except in compliance with the License. You may %
% obtain a copy of the License at %
% %
% http://www.imagemagick.org/script/license.php %
% %
% Unless required by applicable law or agreed to in writing, software %
% distributed under the License is distributed on an "AS IS" BASIS, %
% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
% See the License for the specific language governing permissions and %
% limitations under the License. %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Realism in computer graphics typically requires using 24 bits/pixel to
% generate an image. Yet many graphic display devices do not contain the
% amount of memory necessary to match the spatial and color resolution of
% the human eye. The Quantize methods takes a 24 bit image and reduces
% the number of colors so it can be displayed on raster device with less
% bits per pixel. In most instances, the quantized image closely
% resembles the original reference image.
%
% A reduction of colors in an image is also desirable for image
% transmission and real-time animation.
%
% QuantizeImage() takes a standard RGB or monochrome images and quantizes
% them down to some fixed number of colors.
%
% For purposes of color allocation, an image is a set of n pixels, where
% each pixel is a point in RGB space. RGB space is a 3-dimensional
% vector space, and each pixel, Pi, is defined by an ordered triple of
% red, green, and blue coordinates, (Ri, Gi, Bi).
%
% Each primary color component (red, green, or blue) represents an
% intensity which varies linearly from 0 to a maximum value, Cmax, which
% corresponds to full saturation of that color. Color allocation is
% defined over a domain consisting of the cube in RGB space with opposite
% vertices at (0,0,0) and (Cmax, Cmax, Cmax). QUANTIZE requires Cmax =
% 255.
%
% The algorithm maps this domain onto a tree in which each node
% represents a cube within that domain. In the following discussion
% these cubes are defined by the coordinate of two opposite vertices:
% The vertex nearest the origin in RGB space and the vertex farthest from
% the origin.
%
% The tree's root node represents the entire domain, (0,0,0) through
% (Cmax,Cmax,Cmax). Each lower level in the tree is generated by
% subdividing one node's cube into eight smaller cubes of equal size.
% This corresponds to bisecting the parent cube with planes passing
% through the midpoints of each edge.
%
% The basic algorithm operates in three phases: Classification,
% Reduction, and Assignment. Classification builds a color description
% tree for the image. Reduction collapses the tree until the number it
% represents, at most, the number of colors desired in the output image.
% Assignment defines the output image's color map and sets each pixel's
% color by restorage_class in the reduced tree. Our goal is to minimize
% the numerical discrepancies between the original colors and quantized
% colors (quantization error).
%
% Classification begins by initializing a color description tree of
% sufficient depth to represent each possible input color in a leaf.
% However, it is impractical to generate a fully-formed color description
% tree in the storage_class phase for realistic values of Cmax. If
% colors components in the input image are quantized to k-bit precision,
% so that Cmax= 2k-1, the tree would need k levels below the root node to
% allow representing each possible input color in a leaf. This becomes
% prohibitive because the tree's total number of nodes is 1 +
% sum(i=1, k, 8k).
%
% A complete tree would require 19,173,961 nodes for k = 8, Cmax = 255.
% Therefore, to avoid building a fully populated tree, QUANTIZE: (1)
% Initializes data structures for nodes only as they are needed; (2)
% Chooses a maximum depth for the tree as a function of the desired
% number of colors in the output image (currently log2(colormap size)).
%
% For each pixel in the input image, storage_class scans downward from
% the root of the color description tree. At each level of the tree it
% identifies the single node which represents a cube in RGB space
% containing the pixel's color. It updates the following data for each
% such node:
%
% n1: Number of pixels whose color is contained in the RGB cube which
% this node represents;
%
% n2: Number of pixels whose color is not represented in a node at
% lower depth in the tree; initially, n2 = 0 for all nodes except
% leaves of the tree.
%
% Sr, Sg, Sb: Sums of the red, green, and blue component values for all
% pixels not classified at a lower depth. The combination of these sums
% and n2 will ultimately characterize the mean color of a set of
% pixels represented by this node.
%
% E: the distance squared in RGB space between each pixel contained
% within a node and the nodes' center. This represents the
% quantization error for a node.
%
% Reduction repeatedly prunes the tree until the number of nodes with n2
% > 0 is less than or equal to the maximum number of colors allowed in
% the output image. On any given iteration over the tree, it selects
% those nodes whose E count is minimal for pruning and merges their color
% statistics upward. It uses a pruning threshold, Ep, to govern node
% selection as follows:
%
% Ep = 0
% while number of nodes with (n2 > 0) > required maximum number of colors
% prune all nodes such that E <= Ep
% Set Ep to minimum E in remaining nodes
%
% This has the effect of minimizing any quantization error when merging
% two nodes together.
%
% When a node to be pruned has offspring, the pruning procedure invokes
% itself recursively in order to prune the tree from the leaves upward.
% n2, Sr, Sg, and Sb in a node being pruned are always added to the
% corresponding data in that node's parent. This retains the pruned
% node's color characteristics for later averaging.
%
% For each node, n2 pixels exist for which that node represents the
% smallest volume in RGB space containing those pixel's colors. When n2
% > 0 the node will uniquely define a color in the output image. At the
% beginning of reduction, n2 = 0 for all nodes except a the leaves of
% the tree which represent colors present in the input image.
%
% The other pixel count, n1, indicates the total number of colors within
% the cubic volume which the node represents. This includes n1 - n2
% pixels whose colors should be defined by nodes at a lower level in the
% tree.
%
% Assignment generates the output image from the pruned tree. The output
% image consists of two parts: (1) A color map, which is an array of
% color descriptions (RGB triples) for each color present in the output
% image; (2) A pixel array, which represents each pixel as an index
% into the color map array.
%
% First, the assignment phase makes one pass over the pruned color
% description tree to establish the image's color map. For each node
% with n2 > 0, it divides Sr, Sg, and Sb by n2 . This produces the mean
% color of all pixels that classify no lower than this node. Each of
% these colors becomes an entry in the color map.
%
% Finally, the assignment phase reclassifies each pixel in the pruned
% tree to identify the deepest node containing the pixel's color. The
% pixel's value in the pixel array becomes the index of this node's mean
% color in the color map.
%
% This method is based on a similar algorithm written by Paul Raveling.
%
*/
/*
Include declarations.
*/
#include "magick/studio.h"
#include "magick/cache-view.h"
#include "magick/color.h"
#include "magick/color-private.h"
#include "magick/colorspace.h"
#include "magick/enhance.h"
#include "magick/exception.h"
#include "magick/exception-private.h"
#include "magick/image.h"
#include "magick/image-private.h"
#include "magick/list.h"
#include "magick/memory_.h"
#include "magick/monitor.h"
#include "magick/monitor-private.h"
#include "magick/option.h"
#include "magick/pixel-private.h"
#include "magick/quantize.h"
#include "magick/quantum.h"
#include "magick/string_.h"
/*
Define declarations.
*/
#define CacheShift 2
#define ErrorQueueLength 16
#define MaxNodes 266817
#define MaxTreeDepth 8
#define NodesInAList 1920
/*
Typdef declarations.
*/
typedef struct _RealPixelPacket
{
MagickRealType
red,
green,
blue,
opacity;
} RealPixelPacket;
typedef struct _NodeInfo
{
struct _NodeInfo
*parent,
*child[16];
MagickSizeType
number_unique;
RealPixelPacket
total_color;
MagickRealType
quantize_error;
unsigned long
color_number,
id,
level;
} NodeInfo;
typedef struct _Nodes
{
NodeInfo
*nodes;
struct _Nodes
*next;
} Nodes;
typedef struct _CubeInfo
{
NodeInfo
*root;
unsigned long
colors,
maximum_colors;
long
transparent_index;
MagickSizeType
transparent_pixels;
RealPixelPacket
target;
MagickRealType
distance,
pruning_threshold,
next_threshold;
unsigned long
nodes,
free_nodes,
color_number;
NodeInfo
*next_node;
Nodes
*node_queue;
long
*cache;
RealPixelPacket
error[ErrorQueueLength];
MagickRealType
weights[ErrorQueueLength];
QuantizeInfo
*quantize_info;
MagickBooleanType
associate_alpha;
long
x,
y;
unsigned long
depth;
MagickOffsetType
offset;
MagickSizeType
span;
} CubeInfo;
/*
Method prototypes.
*/
static CubeInfo
*GetCubeInfo(const QuantizeInfo *,const unsigned long,const unsigned long);
static NodeInfo
*GetNodeInfo(CubeInfo *,const unsigned long,const unsigned long,NodeInfo *);
static MagickBooleanType
AssignImageColors(Image *,CubeInfo *),
ClassifyImageColors(CubeInfo *,const Image *,ExceptionInfo *),
DitherImage(Image *,CubeInfo *),
SetGrayscaleImage(Image *);
static unsigned long
DefineImageColormap(Image *,CubeInfo *,NodeInfo *);
static void
ClosestColor(const Image *,CubeInfo *,const NodeInfo *),
DestroyCubeInfo(CubeInfo *),
PruneLevel(const Image *,CubeInfo *,const NodeInfo *),
PruneToCubeDepth(const Image *,CubeInfo *,const NodeInfo *),
ReduceImageColors(const Image *,CubeInfo *);
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% A c q u i r e Q u a n t i z e I n f o %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% AcquireQuantizeInfo() allocates the QuantizeInfo structure.
%
% The format of the AcquireQuantizeInfo method is:
%
% QuantizeInfo *AcquireQuantizeInfo(const ImageInfo *image_info)
%
% A description of each parameter follows:
%
% o image_info: the image info.
%
*/
MagickExport QuantizeInfo *AcquireQuantizeInfo(const ImageInfo *image_info)
{
QuantizeInfo
*quantize_info;
quantize_info=(QuantizeInfo *) AcquireMagickMemory(sizeof(*quantize_info));
if (quantize_info == (QuantizeInfo *) NULL)
ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
GetQuantizeInfo(quantize_info);
if (image_info != (ImageInfo *) NULL)
{
const char
*option;
quantize_info->dither=image_info->dither;
option=GetImageOption(image_info,"dither");
if (option != (const char *) NULL)
quantize_info->dither_method=(DitherMethod) ParseMagickOption(
MagickDitherOptions,MagickFalse,option);
quantize_info->measure_error=image_info->verbose;
}
return(quantize_info);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ A s s i g n I m a g e C o l o r s %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% AssignImageColors() generates the output image from the pruned tree. The
% output image consists of two parts: (1) A color map, which is an array
% of color descriptions (RGB triples) for each color present in the
% output image; (2) A pixel array, which represents each pixel as an
% index into the color map array.
%
% First, the assignment phase makes one pass over the pruned color
% description tree to establish the image's color map. For each node
% with n2 > 0, it divides Sr, Sg, and Sb by n2 . This produces the mean
% color of all pixels that classify no lower than this node. Each of
% these colors becomes an entry in the color map.
%
% Finally, the assignment phase reclassifies each pixel in the pruned
% tree to identify the deepest node containing the pixel's color. The
% pixel's value in the pixel array becomes the index of this node's mean
% color in the color map.
%
% The format of the AssignImageColors() method is:
%
% MagickBooleanType AssignImageColors(Image *image,CubeInfo *cube_info)
%
% A description of each parameter follows.
%
% o image: the image.
%
% o cube_info: A pointer to the Cube structure.
%
*/
static inline void AssociateAlphaPixel(const CubeInfo *cube_info,
const PixelPacket *pixel,RealPixelPacket *alpha_pixel)
{
MagickRealType
alpha;
if ((cube_info->associate_alpha == MagickFalse) ||
(pixel->opacity == OpaqueOpacity))
{
alpha_pixel->red=(MagickRealType) pixel->red;
alpha_pixel->green=(MagickRealType) pixel->green;
alpha_pixel->blue=(MagickRealType) pixel->blue;
alpha_pixel->opacity=(MagickRealType) pixel->opacity;
return;
}
alpha=(MagickRealType) (QuantumScale*(QuantumRange-pixel->opacity));
alpha_pixel->red=alpha*pixel->red;
alpha_pixel->green=alpha*pixel->green;
alpha_pixel->blue=alpha*pixel->blue;
alpha_pixel->opacity=(MagickRealType) pixel->opacity;
}
static inline Quantum ClipToQuantum(const MagickRealType value)
{
if (value <= 0.0)
return((Quantum) 0);
if (value >= QuantumRange)
return((Quantum) QuantumRange);
return((Quantum) (value+0.5));
}
static inline unsigned long ColorToNodeId(const CubeInfo *cube_info,
const RealPixelPacket *pixel,unsigned long index)
{
unsigned long
id;
id=(unsigned long) (
((ScaleQuantumToChar(ClipToQuantum(pixel->red)) >> index) & 0x1) |
((ScaleQuantumToChar(ClipToQuantum(pixel->green)) >> index) & 0x1) << 1 |
((ScaleQuantumToChar(ClipToQuantum(pixel->blue)) >> index) & 0x1) << 2);
if (cube_info->associate_alpha != MagickFalse)
id|=((ScaleQuantumToChar(ClipToQuantum(pixel->opacity)) >> index) & 0x1)
<< 3;
return(id);
}
static inline MagickBooleanType IsSameColor(const Image *image,
const PixelPacket *p,const PixelPacket *q)
{
if ((p->red != q->red) || (p->green != q->green) || (p->blue != q->blue))
return(MagickFalse);
if ((image->matte != MagickFalse) && (p->opacity != q->opacity))
return(MagickFalse);
return(MagickTrue);
}
static MagickBooleanType AssignImageColors(Image *image,CubeInfo *cube_info)
{
#define AssignImageTag "Assign/Image"
long
y;
MagickBooleanType
proceed;
RealPixelPacket
pixel;
register long
i,
x;
register const NodeInfo
*node_info;
ssize_t
count;
unsigned long
id,
index;
/*
Allocate image colormap.
*/
if ((cube_info->quantize_info->colorspace != UndefinedColorspace) &&
(cube_info->quantize_info->colorspace != CMYKColorspace))
(void) TransformImageColorspace((Image *) image,
cube_info->quantize_info->colorspace);
else
if ((image->colorspace != GRAYColorspace) &&
(image->colorspace != RGBColorspace) &&
(image->colorspace != CMYColorspace))
(void) TransformImageColorspace((Image *) image,RGBColorspace);
if (AcquireImageColormap(image,cube_info->colors) == MagickFalse)
ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
image->filename);
image->colors=0;
cube_info->transparent_pixels=0;
cube_info->transparent_index=(-1);
(void) DefineImageColormap(image,cube_info,cube_info->root);
/*
Create a reduced color image.
*/
if ((cube_info->quantize_info->dither != MagickFalse) &&
(cube_info->quantize_info->dither_method != NoDitherMethod))
(void) DitherImage(image,cube_info);
else
{
ExceptionInfo
*exception;
CacheView
*image_view;
exception=(&image->exception);
image_view=AcquireCacheView(image);
for (y=0; y < (long) image->rows; y++)
{
register IndexPacket
*__restrict indexes;
register PixelPacket
*__restrict q;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
exception);
if (q == (PixelPacket *) NULL)
break;
indexes=GetCacheViewAuthenticIndexQueue(image_view);
for (x=0; x < (long) image->columns; x+=count)
{
/*
Identify the deepest node containing the pixel's color.
*/
for (count=1; (x+count) < (long) image->columns; count++)
if (IsSameColor(image,q,q+count) == MagickFalse)
break;
AssociateAlphaPixel(cube_info,q,&pixel);
node_info=cube_info->root;
for (index=MaxTreeDepth-1; (long) index > 0; index--)
{
id=ColorToNodeId(cube_info,&pixel,index);
if (node_info->child[id] == (NodeInfo *) NULL)
break;
node_info=node_info->child[id];
}
/*
Find closest color among siblings and their children.
*/
cube_info->target=pixel;
cube_info->distance=(MagickRealType) (4.0*(QuantumRange+1.0)*
(QuantumRange+1.0)+1.0);
ClosestColor(image,cube_info,node_info->parent);
index=cube_info->color_number;
for (i=0; i < (long) count; i++)
{
if (image->storage_class == PseudoClass)
indexes[x+i]=(IndexPacket) index;
if (cube_info->quantize_info->measure_error == MagickFalse)
{
q->red=image->colormap[index].red;
q->green=image->colormap[index].green;
q->blue=image->colormap[index].blue;
if (cube_info->associate_alpha != MagickFalse)
q->opacity=image->colormap[index].opacity;
}
q++;
}
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
break;
proceed=SetImageProgress(image,AssignImageTag,y,image->rows);
if (proceed == MagickFalse)
break;
}
image_view=DestroyCacheView(image_view);
}
if (cube_info->quantize_info->measure_error != MagickFalse)
(void) GetImageQuantizeError(image);
if ((cube_info->quantize_info->number_colors == 2) &&
(cube_info->quantize_info->colorspace == GRAYColorspace))
{
Quantum
intensity;
register PixelPacket
*__restrict q;
/*
Monochrome image.
*/
q=image->colormap;
for (i=0; i < (long) image->colors; i++)
{
intensity=(Quantum) (PixelIntensity(q) < ((MagickRealType)
QuantumRange/2.0) ? 0 : QuantumRange);
q->red=intensity;
q->green=intensity;
q->blue=intensity;
q++;
}
}
(void) SyncImage(image);
if ((cube_info->quantize_info->colorspace != UndefinedColorspace) &&
(cube_info->quantize_info->colorspace != CMYKColorspace))
(void) TransformImageColorspace((Image *) image,RGBColorspace);
return(MagickTrue);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ C l a s s i f y I m a g e C o l o r s %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% ClassifyImageColors() begins by initializing a color description tree
% of sufficient depth to represent each possible input color in a leaf.
% However, it is impractical to generate a fully-formed color
% description tree in the storage_class phase for realistic values of
% Cmax. If colors components in the input image are quantized to k-bit
% precision, so that Cmax= 2k-1, the tree would need k levels below the
% root node to allow representing each possible input color in a leaf.
% This becomes prohibitive because the tree's total number of nodes is
% 1 + sum(i=1,k,8k).
%
% A complete tree would require 19,173,961 nodes for k = 8, Cmax = 255.
% Therefore, to avoid building a fully populated tree, QUANTIZE: (1)
% Initializes data structures for nodes only as they are needed; (2)
% Chooses a maximum depth for the tree as a function of the desired
% number of colors in the output image (currently log2(colormap size)).
%
% For each pixel in the input image, storage_class scans downward from
% the root of the color description tree. At each level of the tree it
% identifies the single node which represents a cube in RGB space
% containing It updates the following data for each such node:
%
% n1 : Number of pixels whose color is contained in the RGB cube
% which this node represents;
%
% n2 : Number of pixels whose color is not represented in a node at
% lower depth in the tree; initially, n2 = 0 for all nodes except
% leaves of the tree.
%
% Sr, Sg, Sb : Sums of the red, green, and blue component values for
% all pixels not classified at a lower depth. The combination of
% these sums and n2 will ultimately characterize the mean color of a
% set of pixels represented by this node.
%
% E: the distance squared in RGB space between each pixel contained
% within a node and the nodes' center. This represents the quantization
% error for a node.
%
% The format of the ClassifyImageColors() method is:
%
% MagickBooleanType ClassifyImageColors(CubeInfo *cube_info,
% const Image *image,ExceptionInfo *exception)
%
% A description of each parameter follows.
%
% o cube_info: A pointer to the Cube structure.
%
% o image: the image.
%
*/
static inline void SetAssociatedAlpha(const Image *image,CubeInfo *cube_info)
{
MagickBooleanType
associate_alpha;
associate_alpha=image->matte;
if (cube_info->quantize_info->colorspace == TransparentColorspace)
associate_alpha=MagickFalse;
if ((cube_info->quantize_info->number_colors == 2) &&
(cube_info->quantize_info->colorspace == GRAYColorspace))
associate_alpha=MagickFalse;
cube_info->associate_alpha=associate_alpha;
}
static MagickBooleanType ClassifyImageColors(CubeInfo *cube_info,
const Image *image,ExceptionInfo *exception)
{
#define ClassifyImageTag "Classify/Image"
long
y;
MagickBooleanType
proceed;
MagickRealType
bisect;
NodeInfo
*node_info;
RealPixelPacket
error,
mid,
midpoint,
pixel;
size_t
count;
unsigned long
id,
index,
level;
CacheView
*image_view;
/*
Classify the first cube_info->maximum_colors colors to a tree depth of 8.
*/
SetAssociatedAlpha(image,cube_info);
if ((cube_info->quantize_info->colorspace != UndefinedColorspace) &&
(cube_info->quantize_info->colorspace != CMYKColorspace))
(void) TransformImageColorspace((Image *) image,
cube_info->quantize_info->colorspace);
else
if ((image->colorspace != GRAYColorspace) &&
(image->colorspace != CMYColorspace) &&
(image->colorspace != RGBColorspace))
(void) TransformImageColorspace((Image *) image,RGBColorspace);
midpoint.red=(MagickRealType) QuantumRange/2.0;
midpoint.green=(MagickRealType) QuantumRange/2.0;
midpoint.blue=(MagickRealType) QuantumRange/2.0;
midpoint.opacity=(MagickRealType) QuantumRange/2.0;
error.opacity=0.0;
image_view=AcquireCacheView(image);
for (y=0; y < (long) image->rows; y++)
{
register const PixelPacket
*__restrict p;
register long
x;
p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
if (p == (const PixelPacket *) NULL)
break;
if (cube_info->nodes > MaxNodes)
{
/*
Prune one level if the color tree is too large.
*/
PruneLevel(image,cube_info,cube_info->root);
cube_info->depth--;
}
for (x=0; x < (long) image->columns; x+=(long) count)
{
/*
Start at the root and descend the color cube tree.
*/
for (count=1; (x+count) < image->columns; count++)
if (IsSameColor(image,p,p+count) == MagickFalse)
break;
AssociateAlphaPixel(cube_info,p,&pixel);
index=MaxTreeDepth-1;
bisect=((MagickRealType) QuantumRange+1.0)/2.0;
mid=midpoint;
node_info=cube_info->root;
for (level=1; level <= MaxTreeDepth; level++)
{
bisect*=0.5;
id=ColorToNodeId(cube_info,&pixel,index);
mid.red+=(id & 1) != 0 ? bisect : -bisect;
mid.green+=(id & 2) != 0 ? bisect : -bisect;
mid.blue+=(id & 4) != 0 ? bisect : -bisect;
mid.opacity+=(id & 8) != 0 ? bisect : -bisect;
if (node_info->child[id] == (NodeInfo *) NULL)
{
/*
Set colors of new node to contain pixel.
*/
node_info->child[id]=GetNodeInfo(cube_info,id,level,node_info);
if (node_info->child[id] == (NodeInfo *) NULL)
(void) ThrowMagickException(exception,GetMagickModule(),
ResourceLimitError,"MemoryAllocationFailed","`%s'",
image->filename);
if (level == MaxTreeDepth)
cube_info->colors++;
}
/*
Approximate the quantization error represented by this node.
*/
node_info=node_info->child[id];
error.red=QuantumScale*(pixel.red-mid.red);
error.green=QuantumScale*(pixel.green-mid.green);
error.blue=QuantumScale*(pixel.blue-mid.blue);
if (cube_info->associate_alpha != MagickFalse)
error.opacity=QuantumScale*(pixel.opacity-mid.opacity);
node_info->quantize_error+=sqrt((double) (count*error.red*error.red+
count*error.green*error.green+count*error.blue*error.blue+
count*error.opacity*error.opacity));
cube_info->root->quantize_error+=node_info->quantize_error;
index--;
}
/*
Sum RGB for this leaf for later derivation of the mean cube color.
*/
node_info->number_unique+=count;
node_info->total_color.red+=count*QuantumScale*pixel.red;
node_info->total_color.green+=count*QuantumScale*pixel.green;
node_info->total_color.blue+=count*QuantumScale*pixel.blue;
if (cube_info->associate_alpha != MagickFalse)
node_info->total_color.opacity+=count*QuantumScale*pixel.opacity;
p+=count;
}
if (cube_info->colors > cube_info->maximum_colors)
{
PruneToCubeDepth(image,cube_info,cube_info->root);
break;
}
proceed=SetImageProgress(image,ClassifyImageTag,y,image->rows);
if (proceed == MagickFalse)
break;
}
for (y++; y < (long) image->rows; y++)
{
register const PixelPacket
*__restrict p;
register long
x;
p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
if (p == (const PixelPacket *) NULL)
break;
if (cube_info->nodes > MaxNodes)
{
/*
Prune one level if the color tree is too large.
*/
PruneLevel(image,cube_info,cube_info->root);
cube_info->depth--;
}
for (x=0; x < (long) image->columns; x+=(long) count)
{
/*
Start at the root and descend the color cube tree.
*/
for (count=1; (x+count) < image->columns; count++)
if (IsSameColor(image,p,p+count) == MagickFalse)
break;
AssociateAlphaPixel(cube_info,p,&pixel);
index=MaxTreeDepth-1;
bisect=((MagickRealType) QuantumRange+1.0)/2.0;
mid=midpoint;
node_info=cube_info->root;
for (level=1; level <= cube_info->depth; level++)
{
bisect*=0.5;
id=ColorToNodeId(cube_info,&pixel,index);
mid.red+=(id & 1) != 0 ? bisect : -bisect;
mid.green+=(id & 2) != 0 ? bisect : -bisect;
mid.blue+=(id & 4) != 0 ? bisect : -bisect;
mid.opacity+=(id & 8) != 0 ? bisect : -bisect;
if (node_info->child[id] == (NodeInfo *) NULL)
{
/*
Set colors of new node to contain pixel.
*/
node_info->child[id]=GetNodeInfo(cube_info,id,level,node_info);
if (node_info->child[id] == (NodeInfo *) NULL)
(void) ThrowMagickException(exception,GetMagickModule(),
ResourceLimitError,"MemoryAllocationFailed","%s",
image->filename);
if (level == cube_info->depth)
cube_info->colors++;
}
/*
Approximate the quantization error represented by this node.
*/
node_info=node_info->child[id];
error.red=QuantumScale*(pixel.red-mid.red);
error.green=QuantumScale*(pixel.green-mid.green);
error.blue=QuantumScale*(pixel.blue-mid.blue);
if (cube_info->associate_alpha != MagickFalse)
error.opacity=QuantumScale*(pixel.opacity-mid.opacity);
node_info->quantize_error+=sqrt((double) (count*error.red*error.red+
count*error.green*error.green+error.blue*error.blue+
count*error.opacity*error.opacity));
cube_info->root->quantize_error+=node_info->quantize_error;
index--;
}
/*
Sum RGB for this leaf for later derivation of the mean cube color.
*/
node_info->number_unique+=count;
node_info->total_color.red+=count*QuantumScale*pixel.red;
node_info->total_color.green+=count*QuantumScale*pixel.green;
node_info->total_color.blue+=count*QuantumScale*pixel.blue;
if (cube_info->associate_alpha != MagickFalse)
node_info->total_color.opacity+=count*QuantumScale*pixel.opacity;
p+=count;
}
proceed=SetImageProgress(image,ClassifyImageTag,y,image->rows);
if (proceed == MagickFalse)
break;
}
image_view=DestroyCacheView(image_view);
if ((cube_info->quantize_info->colorspace != UndefinedColorspace) &&
(cube_info->quantize_info->colorspace != CMYKColorspace))
(void) TransformImageColorspace((Image *) image,RGBColorspace);
return(MagickTrue);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% C l o n e Q u a n t i z e I n f o %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% CloneQuantizeInfo() makes a duplicate of the given quantize info structure,
% or if quantize info is NULL, a new one.
%
% The format of the CloneQuantizeInfo method is:
%
% QuantizeInfo *CloneQuantizeInfo(const QuantizeInfo *quantize_info)
%
% A description of each parameter follows:
%
% o clone_info: Method CloneQuantizeInfo returns a duplicate of the given
% quantize info, or if image info is NULL a new one.
%
% o quantize_info: a structure of type info.
%
*/
MagickExport QuantizeInfo *CloneQuantizeInfo(const QuantizeInfo *quantize_info)
{
QuantizeInfo
*clone_info;
clone_info=(QuantizeInfo *) AcquireMagickMemory(sizeof(*clone_info));
if (clone_info == (QuantizeInfo *) NULL)
ThrowFatalException(ResourceLimitFatalError,"MemoryAllocationFailed");
GetQuantizeInfo(clone_info);
if (quantize_info == (QuantizeInfo *) NULL)
return(clone_info);
clone_info->number_colors=quantize_info->number_colors;
clone_info->tree_depth=quantize_info->tree_depth;
clone_info->dither=quantize_info->dither;
clone_info->dither_method=quantize_info->dither_method;
clone_info->colorspace=quantize_info->colorspace;
clone_info->measure_error=quantize_info->measure_error;
return(clone_info);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ C l o s e s t C o l o r %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% ClosestColor() traverses the color cube tree at a particular node and
% determines which colormap entry best represents the input color.
%
% The format of the ClosestColor method is:
%
% void ClosestColor(const Image *image,CubeInfo *cube_info,
% const NodeInfo *node_info)
%
% A description of each parameter follows.
%
% o image: the image.
%
% o cube_info: A pointer to the Cube structure.
%
% o node_info: the address of a structure of type NodeInfo which points to a
% node in the color cube tree that is to be pruned.
%
*/
static void ClosestColor(const Image *image,CubeInfo *cube_info,
const NodeInfo *node_info)
{
register long
i;
unsigned long
number_children;
/*
Traverse any children.
*/
number_children=cube_info->associate_alpha == MagickFalse ? 8UL : 16UL;
for (i=0; i < (long) number_children; i++)
if (node_info->child[i] != (NodeInfo *) NULL)
ClosestColor(image,cube_info,node_info->child[i]);
if (node_info->number_unique != 0)
{
MagickRealType
pixel;
register MagickRealType
alpha,
beta,
distance;
register PixelPacket
*__restrict p;
register RealPixelPacket
*__restrict q;
/*
Determine if this color is "closest".
*/
p=image->colormap+node_info->color_number;
q=(&cube_info->target);
alpha=1.0;
beta=1.0;
if (cube_info->associate_alpha == MagickFalse)
{
alpha=(MagickRealType) (QuantumScale*(QuantumRange-p->opacity));
beta=(MagickRealType) (QuantumScale*(QuantumRange-q->opacity));
}
pixel=alpha*p->red-beta*q->red;
distance=pixel*pixel;
if (distance < cube_info->distance)
{
pixel=alpha*p->green-beta*q->green;
distance+=pixel*pixel;
if (distance < cube_info->distance)
{
pixel=alpha*p->blue-beta*q->blue;
distance+=pixel*pixel;
if (distance < cube_info->distance)
{
pixel=alpha-beta;
distance+=pixel*pixel;
if (distance < cube_info->distance)
{
cube_info->distance=distance;
cube_info->color_number=node_info->color_number;
}
}
}
}
}
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% C o m p r e s s I m a g e C o l o r m a p %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% CompressImageColormap() compresses an image colormap by removing any
% duplicate or unused color entries.
%
% The format of the CompressImageColormap method is:
%
% MagickBooleanType CompressImageColormap(Image *image)
%
% A description of each parameter follows:
%
% o image: the image.
%
*/
MagickExport MagickBooleanType CompressImageColormap(Image *image)
{
QuantizeInfo
quantize_info;
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
if (IsPaletteImage(image,&image->exception) == MagickFalse)
return(MagickFalse);
GetQuantizeInfo(&quantize_info);
quantize_info.number_colors=image->colors;
quantize_info.tree_depth=MaxTreeDepth;
return(QuantizeImage(&quantize_info,image));
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ D e f i n e I m a g e C o l o r m a p %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% DefineImageColormap() traverses the color cube tree and notes each colormap
% entry. A colormap entry is any node in the color cube tree where the
% of unique colors is not zero. DefineImageColormap() returns the number of
% colors in the image colormap.
%
% The format of the DefineImageColormap method is:
%
% unsigned long DefineImageColormap(Image *image,CubeInfo *cube_info,
% NodeInfo *node_info)
%
% A description of each parameter follows.
%
% o image: the image.
%
% o cube_info: A pointer to the Cube structure.
%
% o node_info: the address of a structure of type NodeInfo which points to a
% node in the color cube tree that is to be pruned.
%
*/
static unsigned long DefineImageColormap(Image *image,CubeInfo *cube_info,
NodeInfo *node_info)
{
register long
i;
unsigned long
number_children;
/*
Traverse any children.
*/
number_children=cube_info->associate_alpha == MagickFalse ? 8UL : 16UL;
for (i=0; i < (long) number_children; i++)
if (node_info->child[i] != (NodeInfo *) NULL)
DefineImageColormap(image,cube_info,node_info->child[i]);
if (node_info->number_unique != 0)
{
register MagickRealType
alpha;
register PixelPacket
*__restrict q;
/*
Colormap entry is defined by the mean color in this cube.
*/
q=image->colormap+image->colors;
alpha=(MagickRealType) ((MagickOffsetType) node_info->number_unique);
alpha=1.0/(fabs(alpha) <= MagickEpsilon ? 1.0 : alpha);
if (cube_info->associate_alpha == MagickFalse)
{
q->red=RoundToQuantum((MagickRealType) (alpha*QuantumRange*
node_info->total_color.red));
q->green=RoundToQuantum((MagickRealType) (alpha*QuantumRange*
node_info->total_color.green));
q->blue=RoundToQuantum((MagickRealType) (alpha*QuantumRange*
node_info->total_color.blue));
q->opacity=OpaqueOpacity;
}
else
{
MagickRealType
opacity;
opacity=(MagickRealType) (alpha*QuantumRange*
node_info->total_color.opacity);
q->opacity=RoundToQuantum(opacity);
if (q->opacity == OpaqueOpacity)
{
q->red=RoundToQuantum((MagickRealType) (alpha*QuantumRange*
node_info->total_color.red));
q->green=RoundToQuantum((MagickRealType) (alpha*QuantumRange*
node_info->total_color.green));
q->blue=RoundToQuantum((MagickRealType) (alpha*QuantumRange*
node_info->total_color.blue));
}
else
{
MagickRealType
gamma;
gamma=(MagickRealType) (QuantumScale*(QuantumRange-
(MagickRealType) q->opacity));
gamma=1.0/(fabs(gamma) <= MagickEpsilon ? 1.0 : gamma);
q->red=RoundToQuantum((MagickRealType) (alpha*gamma*QuantumRange*
node_info->total_color.red));
q->green=RoundToQuantum((MagickRealType) (alpha*gamma*
QuantumRange*node_info->total_color.green));
q->blue=RoundToQuantum((MagickRealType) (alpha*gamma*QuantumRange*
node_info->total_color.blue));
if (node_info->number_unique > cube_info->transparent_pixels)
{
cube_info->transparent_pixels=node_info->number_unique;
cube_info->transparent_index=(long) image->colors;
}
}
}
node_info->color_number=image->colors++;
}
return(image->colors);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ D e s t r o y C u b e I n f o %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% DestroyCubeInfo() deallocates memory associated with an image.
%
% The format of the DestroyCubeInfo method is:
%
% DestroyCubeInfo(CubeInfo *cube_info)
%
% A description of each parameter follows:
%
% o cube_info: the address of a structure of type CubeInfo.
%
*/
static void DestroyCubeInfo(CubeInfo *cube_info)
{
register Nodes
*nodes;
/*
Release color cube tree storage.
*/
do
{
nodes=cube_info->node_queue->next;
cube_info->node_queue->nodes=(NodeInfo *) RelinquishMagickMemory(
cube_info->node_queue->nodes);
cube_info->node_queue=(Nodes *) RelinquishMagickMemory(
cube_info->node_queue);
cube_info->node_queue=nodes;
} while (cube_info->node_queue != (Nodes *) NULL);
if (cube_info->cache != (long *) NULL)
cube_info->cache=(long *) RelinquishMagickMemory(cube_info->cache);
cube_info->quantize_info=DestroyQuantizeInfo(cube_info->quantize_info);
cube_info=(CubeInfo *) RelinquishMagickMemory(cube_info);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% D e s t r o y Q u a n t i z e I n f o %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% DestroyQuantizeInfo() deallocates memory associated with an QuantizeInfo
% structure.
%
% The format of the DestroyQuantizeInfo method is:
%
% QuantizeInfo *DestroyQuantizeInfo(QuantizeInfo *quantize_info)
%
% A description of each parameter follows:
%
% o quantize_info: Specifies a pointer to an QuantizeInfo structure.
%
*/
MagickExport QuantizeInfo *DestroyQuantizeInfo(QuantizeInfo *quantize_info)
{
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
assert(quantize_info != (QuantizeInfo *) NULL);
assert(quantize_info->signature == MagickSignature);
quantize_info->signature=(~MagickSignature);
quantize_info=(QuantizeInfo *) RelinquishMagickMemory(quantize_info);
return(quantize_info);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ D i t h e r I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% DitherImage() distributes the difference between an original image and
% the corresponding color reduced algorithm to neighboring pixels using
% serpentine-scan Floyd-Steinberg error diffusion. DitherImage returns
% MagickTrue if the image is dithered otherwise MagickFalse.
%
% The format of the DitherImage method is:
%
% MagickBooleanType DitherImage(Image *image,CubeInfo *cube_info)
%
% A description of each parameter follows.
%
% o image: the image.
%
% o cube_info: A pointer to the Cube structure.
%
*/
static MagickBooleanType FloydSteinbergDither(Image *image,CubeInfo *cube_info)
{
#define DitherImageTag "Dither/Image"
ExceptionInfo
*exception;
long
u,
v,
y;
MagickBooleanType
proceed;
RealPixelPacket
color,
*current,
pixel,
*previous,
*scanlines;
register CubeInfo
*p;
unsigned long
index;
CacheView
*image_view;
/*
Distribute quantization error using Floyd-Steinberg.
*/
scanlines=(RealPixelPacket *) AcquireQuantumMemory(image->columns,
2*sizeof(*scanlines));
if (scanlines == (RealPixelPacket *) NULL)
return(MagickFalse);
p=cube_info;
exception=(&image->exception);
image_view=AcquireCacheView(image);
for (y=0; y < (long) image->rows; y++)
{
register IndexPacket
*__restrict indexes;
register long
i,
x;
register PixelPacket
*__restrict q;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
if (q == (PixelPacket *) NULL)
return(MagickFalse);
indexes=GetCacheViewAuthenticIndexQueue(image_view);
current=scanlines+(y & 0x01)*image->columns;
previous=scanlines+((y+1) & 0x01)*image->columns;
v=(y & 0x01) ? -1 : 1;
for (x=0; x < (long) image->columns; x++)
{
u=(y & 0x01) ? (long) image->columns-1-x : x;
AssociateAlphaPixel(cube_info,q+u,&pixel);
if (x > 0)
{
pixel.red+=7*current[u-v].red/16;
pixel.green+=7*current[u-v].green/16;
pixel.blue+=7*current[u-v].blue/16;
if (cube_info->associate_alpha != MagickFalse)
pixel.opacity+=7*current[u-v].opacity/16;
}
if (y > 0)
{
if (x < (long) (image->columns-1))
{
pixel.red+=previous[u+v].red/16;
pixel.green+=previous[u+v].green/16;
pixel.blue+=previous[u+v].blue/16;
if (cube_info->associate_alpha != MagickFalse)
pixel.opacity+=previous[u+v].opacity/16;
}
pixel.red+=5*previous[u].red/16;
pixel.green+=5*previous[u].green/16;
pixel.blue+=5*previous[u].blue/16;
if (cube_info->associate_alpha != MagickFalse)
pixel.opacity+=5*previous[u].opacity/16;
if (x > 0)
{
pixel.red+=3*previous[u-v].red/16;
pixel.green+=3*previous[u-v].green/16;
pixel.blue+=3*previous[u-v].blue/16;
if (cube_info->associate_alpha != MagickFalse)
pixel.opacity+=3*previous[u-v].opacity/16;
}
}
pixel.red=(MagickRealType) ClipToQuantum(pixel.red);
pixel.green=(MagickRealType) ClipToQuantum(pixel.green);
pixel.blue=(MagickRealType) ClipToQuantum(pixel.blue);
if (cube_info->associate_alpha != MagickFalse)
pixel.opacity=(MagickRealType) ClipToQuantum(pixel.opacity);
i=(long) ((ScaleQuantumToChar(ClipToQuantum(pixel.red)) >> CacheShift) |
(ScaleQuantumToChar(ClipToQuantum(pixel.green)) >> CacheShift) << 6 |
(ScaleQuantumToChar(ClipToQuantum(pixel.blue)) >> CacheShift) << 12);
if (cube_info->associate_alpha != MagickFalse)
i|=((ScaleQuantumToChar(ClipToQuantum(pixel.opacity)) >> CacheShift)
<< 18);
if (p->cache[i] < 0)
{
register NodeInfo
*node_info;
register unsigned long
id;
/*
Identify the deepest node containing the pixel's color.
*/
node_info=p->root;
for (index=MaxTreeDepth-1; (long) index > 0; index--)
{
id=ColorToNodeId(cube_info,&pixel,index);
if (node_info->child[id] == (NodeInfo *) NULL)
break;
node_info=node_info->child[id];
}
/*
Find closest color among siblings and their children.
*/
p->target=pixel;
p->distance=(MagickRealType) (4.0*(QuantumRange+1.0)*(QuantumRange+
1.0)+1.0);
ClosestColor(image,p,node_info->parent);
p->cache[i]=(long) p->color_number;
}
/*
Assign pixel to closest colormap entry.
*/
index=(unsigned long) p->cache[i];
if (image->storage_class == PseudoClass)
indexes[u]=(IndexPacket) index;
if (cube_info->quantize_info->measure_error == MagickFalse)
{
(q+u)->red=image->colormap[index].red;
(q+u)->green=image->colormap[index].green;
(q+u)->blue=image->colormap[index].blue;
if (cube_info->associate_alpha != MagickFalse)
(q+u)->opacity=image->colormap[index].opacity;
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
return(MagickFalse);
/*
Store the error.
*/
AssociateAlphaPixel(cube_info,image->colormap+index,&color);
current[u].red=pixel.red-color.red;
current[u].green=pixel.green-color.green;
current[u].blue=pixel.blue-color.blue;
if (cube_info->associate_alpha != MagickFalse)
current[u].opacity=pixel.opacity-color.opacity;
proceed=SetImageProgress(image,DitherImageTag,p->offset,p->span);
if (proceed == MagickFalse)
return(MagickFalse);
p->offset++;
}
}
scanlines=(RealPixelPacket *) RelinquishMagickMemory(scanlines);
image_view=DestroyCacheView(image_view);
return(MagickTrue);
}
static MagickBooleanType
RiemersmaDither(Image *,CacheView *,CubeInfo *,const unsigned int);
static void Riemersma(Image *image,CacheView *image_view,CubeInfo *cube_info,
const unsigned long level,const unsigned int direction)
{
if (level == 1)
switch (direction)
{
case WestGravity:
{
(void) RiemersmaDither(image,image_view,cube_info,EastGravity);
(void) RiemersmaDither(image,image_view,cube_info,SouthGravity);
(void) RiemersmaDither(image,image_view,cube_info,WestGravity);
break;
}
case EastGravity:
{
(void) RiemersmaDither(image,image_view,cube_info,WestGravity);
(void) RiemersmaDither(image,image_view,cube_info,NorthGravity);
(void) RiemersmaDither(image,image_view,cube_info,EastGravity);
break;
}
case NorthGravity:
{
(void) RiemersmaDither(image,image_view,cube_info,SouthGravity);
(void) RiemersmaDither(image,image_view,cube_info,EastGravity);
(void) RiemersmaDither(image,image_view,cube_info,NorthGravity);
break;
}
case SouthGravity:
{
(void) RiemersmaDither(image,image_view,cube_info,NorthGravity);
(void) RiemersmaDither(image,image_view,cube_info,WestGravity);
(void) RiemersmaDither(image,image_view,cube_info,SouthGravity);
break;
}
default:
break;
}
else
switch (direction)
{
case WestGravity:
{
Riemersma(image,image_view,cube_info,level-1,NorthGravity);
(void) RiemersmaDither(image,image_view,cube_info,EastGravity);
Riemersma(image,image_view,cube_info,level-1,WestGravity);
(void) RiemersmaDither(image,image_view,cube_info,SouthGravity);
Riemersma(image,image_view,cube_info,level-1,WestGravity);
(void) RiemersmaDither(image,image_view,cube_info,WestGravity);
Riemersma(image,image_view,cube_info,level-1,SouthGravity);
break;
}
case EastGravity:
{
Riemersma(image,image_view,cube_info,level-1,SouthGravity);
(void) RiemersmaDither(image,image_view,cube_info,WestGravity);
Riemersma(image,image_view,cube_info,level-1,EastGravity);
(void) RiemersmaDither(image,image_view,cube_info,NorthGravity);
Riemersma(image,image_view,cube_info,level-1,EastGravity);
(void) RiemersmaDither(image,image_view,cube_info,EastGravity);
Riemersma(image,image_view,cube_info,level-1,NorthGravity);
break;
}
case NorthGravity:
{
Riemersma(image,image_view,cube_info,level-1,WestGravity);
(void) RiemersmaDither(image,image_view,cube_info,SouthGravity);
Riemersma(image,image_view,cube_info,level-1,NorthGravity);
(void) RiemersmaDither(image,image_view,cube_info,EastGravity);
Riemersma(image,image_view,cube_info,level-1,NorthGravity);
(void) RiemersmaDither(image,image_view,cube_info,NorthGravity);
Riemersma(image,image_view,cube_info,level-1,EastGravity);
break;
}
case SouthGravity:
{
Riemersma(image,image_view,cube_info,level-1,EastGravity);
(void) RiemersmaDither(image,image_view,cube_info,NorthGravity);
Riemersma(image,image_view,cube_info,level-1,SouthGravity);
(void) RiemersmaDither(image,image_view,cube_info,WestGravity);
Riemersma(image,image_view,cube_info,level-1,SouthGravity);
(void) RiemersmaDither(image,image_view,cube_info,SouthGravity);
Riemersma(image,image_view,cube_info,level-1,WestGravity);
break;
}
default:
break;
}
}
static MagickBooleanType RiemersmaDither(Image *image,CacheView *image_view,
CubeInfo *cube_info,const unsigned int direction)
{
#define DitherImageTag "Dither/Image"
MagickBooleanType
proceed;
RealPixelPacket
color,
pixel;
register CubeInfo
*p;
unsigned long
index;
p=cube_info;
if ((p->x >= 0) && (p->x < (long) image->columns) &&
(p->y >= 0) && (p->y < (long) image->rows))
{
ExceptionInfo
*exception;
register IndexPacket
*__restrict indexes;
register long
i;
register PixelPacket
*__restrict q;
/*
Distribute error.
*/
exception=(&image->exception);
q=GetCacheViewAuthenticPixels(image_view,p->x,p->y,1,1,exception);
if (q == (PixelPacket *) NULL)
return(MagickFalse);
indexes=GetCacheViewAuthenticIndexQueue(image_view);
AssociateAlphaPixel(cube_info,q,&pixel);
for (i=0; i < ErrorQueueLength; i++)
{
pixel.red+=p->weights[i]*p->error[i].red;
pixel.green+=p->weights[i]*p->error[i].green;
pixel.blue+=p->weights[i]*p->error[i].blue;
if (cube_info->associate_alpha != MagickFalse)
pixel.opacity+=p->weights[i]*p->error[i].opacity;
}
pixel.red=(MagickRealType) ClipToQuantum(pixel.red);
pixel.green=(MagickRealType) ClipToQuantum(pixel.green);
pixel.blue=(MagickRealType) ClipToQuantum(pixel.blue);
if (cube_info->associate_alpha != MagickFalse)
pixel.opacity=(MagickRealType) ClipToQuantum(pixel.opacity);
i=(long) ((ScaleQuantumToChar(ClipToQuantum(pixel.red)) >> CacheShift) |
(ScaleQuantumToChar(ClipToQuantum(pixel.green)) >> CacheShift) << 6 |
(ScaleQuantumToChar(ClipToQuantum(pixel.blue)) >> CacheShift) << 12);
if (cube_info->associate_alpha != MagickFalse)
i|=((ScaleQuantumToChar(ClipToQuantum(pixel.opacity)) >> CacheShift)
<< 18);
if (p->cache[i] < 0)
{
register NodeInfo
*node_info;
register unsigned long
id;
/*
Identify the deepest node containing the pixel's color.
*/
node_info=p->root;
for (index=MaxTreeDepth-1; (long) index > 0; index--)
{
id=ColorToNodeId(cube_info,&pixel,index);
if (node_info->child[id] == (NodeInfo *) NULL)
break;
node_info=node_info->child[id];
}
/*
Find closest color among siblings and their children.
*/
p->target=pixel;
p->distance=(MagickRealType) (4.0*(QuantumRange+1.0)*((MagickRealType)
QuantumRange+1.0)+1.0);
ClosestColor(image,p,node_info->parent);
p->cache[i]=(long) p->color_number;
}
/*
Assign pixel to closest colormap entry.
*/
index=(unsigned long) (1*p->cache[i]);
if (image->storage_class == PseudoClass)
*indexes=(IndexPacket) index;
if (cube_info->quantize_info->measure_error == MagickFalse)
{
q->red=image->colormap[index].red;
q->green=image->colormap[index].green;
q->blue=image->colormap[index].blue;
if (cube_info->associate_alpha != MagickFalse)
q->opacity=image->colormap[index].opacity;
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
return(MagickFalse);
/*
Propagate the error as the last entry of the error queue.
*/
(void) CopyMagickMemory(p->error,p->error+1,(ErrorQueueLength-1)*
sizeof(p->error[0]));
AssociateAlphaPixel(cube_info,image->colormap+index,&color);
p->error[ErrorQueueLength-1].red=pixel.red-color.red;
p->error[ErrorQueueLength-1].green=pixel.green-color.green;
p->error[ErrorQueueLength-1].blue=pixel.blue-color.blue;
if (cube_info->associate_alpha != MagickFalse)
p->error[ErrorQueueLength-1].opacity=pixel.opacity-color.opacity;
proceed=SetImageProgress(image,DitherImageTag,p->offset,p->span);
if (proceed == MagickFalse)
return(MagickFalse);
p->offset++;
}
switch (direction)
{
case WestGravity: p->x--; break;
case EastGravity: p->x++; break;
case NorthGravity: p->y--; break;
case SouthGravity: p->y++; break;
}
return(MagickTrue);
}
static inline long MagickMax(const long x,const long y)
{
if (x > y)
return(x);
return(y);
}
static inline long MagickMin(const long x,const long y)
{
if (x < y)
return(x);
return(y);
}
static MagickBooleanType DitherImage(Image *image,CubeInfo *cube_info)
{
MagickBooleanType
status;
register long
i;
unsigned long
depth;
CacheView
*image_view;
if (cube_info->quantize_info->dither_method == FloydSteinbergDitherMethod)
return(FloydSteinbergDither(image,cube_info));
/*
Distribute quantization error along a Hilbert curve.
*/
(void) ResetMagickMemory(cube_info->error,0,ErrorQueueLength*
sizeof(*cube_info->error));
cube_info->x=0;
cube_info->y=0;
i=MagickMax((long) image->columns,(long) image->rows);
for (depth=1; i != 0; depth++)
i>>=1;
if ((long) (1L << depth) < MagickMax((long) image->columns,(long) image->rows))
depth++;
cube_info->offset=0;
cube_info->span=(MagickSizeType) image->columns*image->rows;
image_view=AcquireCacheView(image);
if (depth > 1)
Riemersma(image,image_view,cube_info,depth-1,NorthGravity);
status=RiemersmaDither(image,image_view,cube_info,ForgetGravity);
image_view=DestroyCacheView(image_view);
return(status);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ G e t C u b e I n f o %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetCubeInfo() initialize the Cube data structure.
%
% The format of the GetCubeInfo method is:
%
% CubeInfo GetCubeInfo(const QuantizeInfo *quantize_info,
% const unsigned long depth,const unsigned long maximum_colors)
%
% A description of each parameter follows.
%
% o quantize_info: Specifies a pointer to an QuantizeInfo structure.
%
% o depth: Normally, this integer value is zero or one. A zero or
% one tells Quantize to choose a optimal tree depth of Log4(number_colors).
% A tree of this depth generally allows the best representation of the
% reference image with the least amount of memory and the fastest
% computational speed. In some cases, such as an image with low color
% dispersion (a few number of colors), a value other than
% Log4(number_colors) is required. To expand the color tree completely,
% use a value of 8.
%
% o maximum_colors: maximum colors.
%
*/
static CubeInfo *GetCubeInfo(const QuantizeInfo *quantize_info,
const unsigned long depth,const unsigned long maximum_colors)
{
CubeInfo
*cube_info;
MagickRealType
sum,
weight;
size_t
length;
register long
i;
/*
Initialize tree to describe color cube_info.
*/
cube_info=(CubeInfo *) AcquireMagickMemory(sizeof(*cube_info));
if (cube_info == (CubeInfo *) NULL)
return((CubeInfo *) NULL);
(void) ResetMagickMemory(cube_info,0,sizeof(*cube_info));
cube_info->depth=depth;
if (cube_info->depth > MaxTreeDepth)
cube_info->depth=MaxTreeDepth;
if (cube_info->depth < 2)
cube_info->depth=2;
cube_info->maximum_colors=maximum_colors;
/*
Initialize root node.
*/
cube_info->root=GetNodeInfo(cube_info,0,0,(NodeInfo *) NULL);
if (cube_info->root == (NodeInfo *) NULL)
return((CubeInfo *) NULL);
cube_info->root->parent=cube_info->root;
cube_info->quantize_info=CloneQuantizeInfo(quantize_info);
if (cube_info->quantize_info->dither == MagickFalse)
return(cube_info);
/*
Initialize dither resources.
*/
length=(size_t) (1UL << (4*(8-CacheShift)));
cube_info->cache=(long *) AcquireQuantumMemory(length,
sizeof(*cube_info->cache));
if (cube_info->cache == (long *) NULL)
return((CubeInfo *) NULL);
/*
Initialize color cache.
*/
for (i=0; i < (long) length; i++)
cube_info->cache[i]=(-1);
/*
Distribute weights along a curve of exponential decay.
*/
weight=1.0;
for (i=0; i < ErrorQueueLength; i++)
{
cube_info->weights[ErrorQueueLength-i-1]=1.0/weight;
weight*=exp(log(((double) QuantumRange+1.0))/(ErrorQueueLength-1.0));
}
/*
Normalize the weighting factors.
*/
weight=0.0;
for (i=0; i < ErrorQueueLength; i++)
weight+=cube_info->weights[i];
sum=0.0;
for (i=0; i < ErrorQueueLength; i++)
{
cube_info->weights[i]/=weight;
sum+=cube_info->weights[i];
}
cube_info->weights[0]+=1.0-sum;
return(cube_info);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ G e t N o d e I n f o %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetNodeInfo() allocates memory for a new node in the color cube tree and
% presets all fields to zero.
%
% The format of the GetNodeInfo method is:
%
% NodeInfo *GetNodeInfo(CubeInfo *cube_info,const unsigned long id,
% const unsigned long level,NodeInfo *parent)
%
% A description of each parameter follows.
%
% o node: The GetNodeInfo method returns a pointer to a queue of nodes.
%
% o id: Specifies the child number of the node.
%
% o level: Specifies the level in the storage_class the node resides.
%
*/
static NodeInfo *GetNodeInfo(CubeInfo *cube_info,const unsigned long id,
const unsigned long level,NodeInfo *parent)
{
NodeInfo
*node_info;
if (cube_info->free_nodes == 0)
{
Nodes
*nodes;
/*
Allocate a new queue of nodes.
*/
nodes=(Nodes *) AcquireMagickMemory(sizeof(*nodes));
if (nodes == (Nodes *) NULL)
return((NodeInfo *) NULL);
nodes->nodes=(NodeInfo *) AcquireQuantumMemory(NodesInAList,
sizeof(*nodes->nodes));
if (nodes->nodes == (NodeInfo *) NULL)
return((NodeInfo *) NULL);
nodes->next=cube_info->node_queue;
cube_info->node_queue=nodes;
cube_info->next_node=nodes->nodes;
cube_info->free_nodes=NodesInAList;
}
cube_info->nodes++;
cube_info->free_nodes--;
node_info=cube_info->next_node++;
(void) ResetMagickMemory(node_info,0,sizeof(*node_info));
node_info->parent=parent;
node_info->id=id;
node_info->level=level;
return(node_info);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% G e t I m a g e Q u a n t i z e E r r o r %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetImageQuantizeError() measures the difference between the original
% and quantized images. This difference is the total quantization error.
% The error is computed by summing over all pixels in an image the distance
% squared in RGB space between each reference pixel value and its quantized
% value. These values are computed:
%
% o mean_error_per_pixel: This value is the mean error for any single
% pixel in the image.
%
% o normalized_mean_square_error: This value is the normalized mean
% quantization error for any single pixel in the image. This distance
% measure is normalized to a range between 0 and 1. It is independent
% of the range of red, green, and blue values in the image.
%
% o normalized_maximum_square_error: Thsi value is the normalized
% maximum quantization error for any single pixel in the image. This
% distance measure is normalized to a range between 0 and 1. It is
% independent of the range of red, green, and blue values in your image.
%
% The format of the GetImageQuantizeError method is:
%
% MagickBooleanType GetImageQuantizeError(Image *image)
%
% A description of each parameter follows.
%
% o image: the image.
%
*/
MagickExport MagickBooleanType GetImageQuantizeError(Image *image)
{
ExceptionInfo
*exception;
IndexPacket
*indexes;
long
y;
MagickRealType
alpha,
area,
beta,
distance,
maximum_error,
mean_error,
mean_error_per_pixel;
unsigned long
index;
CacheView
*image_view;
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
image->total_colors=GetNumberColors(image,(FILE *) NULL,&image->exception);
(void) ResetMagickMemory(&image->error,0,sizeof(image->error));
if (image->storage_class == DirectClass)
return(MagickTrue);
alpha=1.0;
beta=1.0;
area=3.0*image->columns*image->rows;
maximum_error=0.0;
mean_error_per_pixel=0.0;
mean_error=0.0;
exception=(&image->exception);
image_view=AcquireCacheView(image);
for (y=0; y < (long) image->rows; y++)
{
register const PixelPacket
*__restrict p;
register long
x;
p=GetCacheViewVirtualPixels(image_view,0,y,image->columns,1,exception);
if (p == (const PixelPacket *) NULL)
break;
indexes=GetCacheViewAuthenticIndexQueue(image_view);
for (x=0; x < (long) image->columns; x++)
{
index=1UL*indexes[x];
if (image->matte != MagickFalse)
{
alpha=(MagickRealType) (QuantumScale*(QuantumRange-p->opacity));
beta=(MagickRealType) (QuantumScale*(QuantumRange-
image->colormap[index].opacity));
}
distance=fabs(alpha*p->red-beta*image->colormap[index].red);
mean_error_per_pixel+=distance;
mean_error+=distance*distance;
if (distance > maximum_error)
maximum_error=distance;
distance=fabs(alpha*p->green-beta*image->colormap[index].green);
mean_error_per_pixel+=distance;
mean_error+=distance*distance;
if (distance > maximum_error)
maximum_error=distance;
distance=fabs(alpha*p->blue-beta*image->colormap[index].blue);
mean_error_per_pixel+=distance;
mean_error+=distance*distance;
if (distance > maximum_error)
maximum_error=distance;
p++;
}
}
image_view=DestroyCacheView(image_view);
image->error.mean_error_per_pixel=(double) mean_error_per_pixel/area;
image->error.normalized_mean_error=(double) QuantumScale*QuantumScale*
mean_error/area;
image->error.normalized_maximum_error=(double) QuantumScale*maximum_error;
return(MagickTrue);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% G e t Q u a n t i z e I n f o %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% GetQuantizeInfo() initializes the QuantizeInfo structure.
%
% The format of the GetQuantizeInfo method is:
%
% GetQuantizeInfo(QuantizeInfo *quantize_info)
%
% A description of each parameter follows:
%
% o quantize_info: Specifies a pointer to a QuantizeInfo structure.
%
*/
MagickExport void GetQuantizeInfo(QuantizeInfo *quantize_info)
{
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"...");
assert(quantize_info != (QuantizeInfo *) NULL);
(void) ResetMagickMemory(quantize_info,0,sizeof(*quantize_info));
quantize_info->number_colors=256;
quantize_info->dither=MagickTrue;
quantize_info->dither_method=RiemersmaDitherMethod;
quantize_info->colorspace=UndefinedColorspace;
quantize_info->measure_error=MagickFalse;
quantize_info->signature=MagickSignature;
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% P o s t e r i z e I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% PosterizeImage() reduces the image to a limited number of colors for a
% "poster" effect.
%
% The format of the PosterizeImage method is:
%
% MagickBooleanType PosterizeImage(Image *image,const unsigned long levels,
% const MagickBooleanType dither)
%
% A description of each parameter follows:
%
% o image: Specifies a pointer to an Image structure.
%
% o levels: Number of color levels allowed in each channel. Very low values
% (2, 3, or 4) have the most visible effect.
%
% o dither: Set this integer value to something other than zero to
% dither the mapped image.
%
*/
MagickExport MagickBooleanType PosterizeImage(Image *image,
const unsigned long levels,const MagickBooleanType dither)
{
ExceptionInfo
*exception;
Image
*posterize_image;
IndexPacket
*indexes;
long
j,
k,
l,
n;
MagickBooleanType
status;
QuantizeInfo
*quantize_info;
register long
i;
register PixelPacket
*__restrict q;
CacheView
*posterize_view;
/*
Posterize image.
*/
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
posterize_image=AcquireImage((ImageInfo *) NULL);
if (posterize_image == (Image *) NULL)
return(MagickFalse);
l=1;
while ((l*l*l) < (long) MagickMin((long) levels*levels*levels,MaxColormapSize+1))
l++;
status=SetImageExtent(posterize_image,(unsigned long) (l*l*l),1);
if (status == MagickFalse)
{
posterize_image=DestroyImage(posterize_image);
return(MagickFalse);
}
status=AcquireImageColormap(posterize_image,levels*levels*levels);
if (status == MagickFalse)
{
posterize_image=DestroyImage(posterize_image);
return(MagickFalse);
}
posterize_view=AcquireCacheView(posterize_image);
exception=(&image->exception);
q=QueueCacheViewAuthenticPixels(posterize_view,0,0,posterize_image->columns,1,
exception);
if (q == (PixelPacket *) NULL)
{
posterize_view=DestroyCacheView(posterize_view);
posterize_image=DestroyImage(posterize_image);
return(MagickFalse);
}
indexes=GetCacheViewAuthenticIndexQueue(posterize_view);
n=0;
for (i=0; i < l; i++)
for (j=0; j < l; j++)
for (k=0; k < l; k++)
{
posterize_image->colormap[n].red=(Quantum) (QuantumRange*i/
MagickMax(l-1L,1L));
posterize_image->colormap[n].green=(Quantum)
(QuantumRange*j/MagickMax(l-1L,1L));
posterize_image->colormap[n].blue=(Quantum) (QuantumRange*k/
MagickMax(l-1L,1L));
posterize_image->colormap[n].opacity=OpaqueOpacity;
*q++=posterize_image->colormap[n];
indexes[n]=(IndexPacket) n;
n++;
}
if (SyncCacheViewAuthenticPixels(posterize_view,exception) == MagickFalse)
{
posterize_view=DestroyCacheView(posterize_view);
posterize_image=DestroyImage(posterize_image);
return(MagickFalse);
}
posterize_view=DestroyCacheView(posterize_view);
quantize_info=AcquireQuantizeInfo((ImageInfo *) NULL);
quantize_info->dither=dither;
status=RemapImage(quantize_info,image,posterize_image);
quantize_info=DestroyQuantizeInfo(quantize_info);
posterize_image=DestroyImage(posterize_image);
return(status);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ P r u n e C h i l d %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% PruneChild() deletes the given node and merges its statistics into its
% parent.
%
% The format of the PruneSubtree method is:
%
% PruneChild(const Image *image,CubeInfo *cube_info,
% const NodeInfo *node_info)
%
% A description of each parameter follows.
%
% o image: the image.
%
% o cube_info: A pointer to the Cube structure.
%
% o node_info: pointer to node in color cube tree that is to be pruned.
%
*/
static void PruneChild(const Image *image,CubeInfo *cube_info,
const NodeInfo *node_info)
{
NodeInfo
*parent;
register long
i;
unsigned long
number_children;
/*
Traverse any children.
*/
number_children=cube_info->associate_alpha == MagickFalse ? 8UL : 16UL;
for (i=0; i < (long) number_children; i++)
if (node_info->child[i] != (NodeInfo *) NULL)
PruneChild(image,cube_info,node_info->child[i]);
/*
Merge color statistics into parent.
*/
parent=node_info->parent;
parent->number_unique+=node_info->number_unique;
parent->total_color.red+=node_info->total_color.red;
parent->total_color.green+=node_info->total_color.green;
parent->total_color.blue+=node_info->total_color.blue;
parent->total_color.opacity+=node_info->total_color.opacity;
parent->child[node_info->id]=(NodeInfo *) NULL;
cube_info->nodes--;
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ P r u n e L e v e l %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% PruneLevel() deletes all nodes at the bottom level of the color tree merging
% their color statistics into their parent node.
%
% The format of the PruneLevel method is:
%
% PruneLevel(const Image *image,CubeInfo *cube_info,
% const NodeInfo *node_info)
%
% A description of each parameter follows.
%
% o image: the image.
%
% o cube_info: A pointer to the Cube structure.
%
% o node_info: pointer to node in color cube tree that is to be pruned.
%
*/
static void PruneLevel(const Image *image,CubeInfo *cube_info,
const NodeInfo *node_info)
{
register long
i;
unsigned long
number_children;
/*
Traverse any children.
*/
number_children=cube_info->associate_alpha == MagickFalse ? 8UL : 16UL;
for (i=0; i < (long) number_children; i++)
if (node_info->child[i] != (NodeInfo *) NULL)
PruneLevel(image,cube_info,node_info->child[i]);
if (node_info->level == cube_info->depth)
PruneChild(image,cube_info,node_info);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ P r u n e T o C u b e D e p t h %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% PruneToCubeDepth() deletes any nodes at a depth greater than
% cube_info->depth while merging their color statistics into their parent
% node.
%
% The format of the PruneToCubeDepth method is:
%
% PruneToCubeDepth(const Image *image,CubeInfo *cube_info,
% const NodeInfo *node_info)
%
% A description of each parameter follows.
%
% o cube_info: A pointer to the Cube structure.
%
% o node_info: pointer to node in color cube tree that is to be pruned.
%
*/
static void PruneToCubeDepth(const Image *image,CubeInfo *cube_info,
const NodeInfo *node_info)
{
register long
i;
unsigned long
number_children;
/*
Traverse any children.
*/
number_children=cube_info->associate_alpha == MagickFalse ? 8UL : 16UL;
for (i=0; i < (long) number_children; i++)
if (node_info->child[i] != (NodeInfo *) NULL)
PruneToCubeDepth(image,cube_info,node_info->child[i]);
if (node_info->level > cube_info->depth)
PruneChild(image,cube_info,node_info);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% Q u a n t i z e I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% QuantizeImage() analyzes the colors within a reference image and chooses a
% fixed number of colors to represent the image. The goal of the algorithm
% is to minimize the color difference between the input and output image while
% minimizing the processing time.
%
% The format of the QuantizeImage method is:
%
% MagickBooleanType QuantizeImage(const QuantizeInfo *quantize_info,
% Image *image)
%
% A description of each parameter follows:
%
% o quantize_info: Specifies a pointer to an QuantizeInfo structure.
%
% o image: the image.
%
*/
MagickExport MagickBooleanType QuantizeImage(const QuantizeInfo *quantize_info,
Image *image)
{
CubeInfo
*cube_info;
MagickBooleanType
status;
unsigned long
depth,
maximum_colors;
assert(quantize_info != (const QuantizeInfo *) NULL);
assert(quantize_info->signature == MagickSignature);
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
maximum_colors=quantize_info->number_colors;
if (maximum_colors == 0)
maximum_colors=MaxColormapSize;
if (maximum_colors > MaxColormapSize)
maximum_colors=MaxColormapSize;
if ((IsGrayImage(image,&image->exception) != MagickFalse) &&
(image->matte == MagickFalse))
(void) SetGrayscaleImage(image);
if ((image->storage_class == PseudoClass) &&
(image->colors <= maximum_colors))
return(MagickTrue);
depth=quantize_info->tree_depth;
if (depth == 0)
{
unsigned long
colors;
/*
Depth of color tree is: Log4(colormap size)+2.
*/
colors=maximum_colors;
for (depth=1; colors != 0; depth++)
colors>>=2;
if ((quantize_info->dither != MagickFalse) && (depth > 2))
depth--;
if ((image->matte != MagickFalse) && (depth > 5))
depth--;
}
/*
Initialize color cube.
*/
cube_info=GetCubeInfo(quantize_info,depth,maximum_colors);
if (cube_info == (CubeInfo *) NULL)
ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
image->filename);
status=ClassifyImageColors(cube_info,image,&image->exception);
if (status != MagickFalse)
{
/*
Reduce the number of colors in the image.
*/
ReduceImageColors(image,cube_info);
status=AssignImageColors(image,cube_info);
}
DestroyCubeInfo(cube_info);
return(status);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% Q u a n t i z e I m a g e s %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% QuantizeImages() analyzes the colors within a set of reference images and
% chooses a fixed number of colors to represent the set. The goal of the
% algorithm is to minimize the color difference between the input and output
% images while minimizing the processing time.
%
% The format of the QuantizeImages method is:
%
% MagickBooleanType QuantizeImages(const QuantizeInfo *quantize_info,
% Image *images)
%
% A description of each parameter follows:
%
% o quantize_info: Specifies a pointer to an QuantizeInfo structure.
%
% o images: Specifies a pointer to a list of Image structures.
%
*/
MagickExport MagickBooleanType QuantizeImages(const QuantizeInfo *quantize_info,
Image *images)
{
CubeInfo
*cube_info;
Image
*image;
MagickBooleanType
proceed,
status;
MagickProgressMonitor
progress_monitor;
register long
i;
unsigned long
depth,
maximum_colors,
number_images;
assert(quantize_info != (const QuantizeInfo *) NULL);
assert(quantize_info->signature == MagickSignature);
assert(images != (Image *) NULL);
assert(images->signature == MagickSignature);
if (images->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",images->filename);
if (GetNextImageInList(images) == (Image *) NULL)
{
/*
Handle a single image with QuantizeImage.
*/
status=QuantizeImage(quantize_info,images);
return(status);
}
status=MagickFalse;
maximum_colors=quantize_info->number_colors;
if (maximum_colors == 0)
maximum_colors=MaxColormapSize;
if (maximum_colors > MaxColormapSize)
maximum_colors=MaxColormapSize;
depth=quantize_info->tree_depth;
if (depth == 0)
{
unsigned long
colors;
/*
Depth of color tree is: Log4(colormap size)+2.
*/
colors=maximum_colors;
for (depth=1; colors != 0; depth++)
colors>>=2;
if (quantize_info->dither != MagickFalse)
depth--;
}
/*
Initialize color cube.
*/
cube_info=GetCubeInfo(quantize_info,depth,maximum_colors);
if (cube_info == (CubeInfo *) NULL)
{
(void) ThrowMagickException(&images->exception,GetMagickModule(),
ResourceLimitError,"MemoryAllocationFailed","`%s'",images->filename);
return(MagickFalse);
}
number_images=GetImageListLength(images);
image=images;
for (i=0; image != (Image *) NULL; i++)
{
progress_monitor=SetImageProgressMonitor(image,(MagickProgressMonitor) NULL,
image->client_data);
status=ClassifyImageColors(cube_info,image,&image->exception);
if (status == MagickFalse)
break;
(void) SetImageProgressMonitor(image,progress_monitor,image->client_data);
proceed=SetImageProgress(image,AssignImageTag,i,number_images);
if (proceed == MagickFalse)
break;
image=GetNextImageInList(image);
}
if (status != MagickFalse)
{
/*
Reduce the number of colors in an image sequence.
*/
ReduceImageColors(images,cube_info);
image=images;
for (i=0; image != (Image *) NULL; i++)
{
progress_monitor=SetImageProgressMonitor(image,(MagickProgressMonitor)
NULL,image->client_data);
status=AssignImageColors(image,cube_info);
if (status == MagickFalse)
break;
(void) SetImageProgressMonitor(image,progress_monitor,
image->client_data);
proceed=SetImageProgress(image,AssignImageTag,i,number_images);
if (proceed == MagickFalse)
break;
image=GetNextImageInList(image);
}
}
DestroyCubeInfo(cube_info);
return(status);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ R e d u c e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% Reduce() traverses the color cube tree and prunes any node whose
% quantization error falls below a particular threshold.
%
% The format of the Reduce method is:
%
% Reduce(const Image *image,CubeInfo *cube_info,const NodeInfo *node_info)
%
% A description of each parameter follows.
%
% o image: the image.
%
% o cube_info: A pointer to the Cube structure.
%
% o node_info: pointer to node in color cube tree that is to be pruned.
%
*/
static void Reduce(const Image *image,CubeInfo *cube_info,
const NodeInfo *node_info)
{
register long
i;
unsigned long
number_children;
/*
Traverse any children.
*/
number_children=cube_info->associate_alpha == MagickFalse ? 8UL : 16UL;
for (i=0; i < (long) number_children; i++)
if (node_info->child[i] != (NodeInfo *) NULL)
Reduce(image,cube_info,node_info->child[i]);
if (node_info->quantize_error <= cube_info->pruning_threshold)
PruneChild(image,cube_info,node_info);
else
{
/*
Find minimum pruning threshold.
*/
if (node_info->number_unique > 0)
cube_info->colors++;
if (node_info->quantize_error < cube_info->next_threshold)
cube_info->next_threshold=node_info->quantize_error;
}
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
+ R e d u c e I m a g e C o l o r s %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% ReduceImageColors() repeatedly prunes the tree until the number of nodes
% with n2 > 0 is less than or equal to the maximum number of colors allowed
% in the output image. On any given iteration over the tree, it selects
% those nodes whose E value is minimal for pruning and merges their
% color statistics upward. It uses a pruning threshold, Ep, to govern
% node selection as follows:
%
% Ep = 0
% while number of nodes with (n2 > 0) > required maximum number of colors
% prune all nodes such that E <= Ep
% Set Ep to minimum E in remaining nodes
%
% This has the effect of minimizing any quantization error when merging
% two nodes together.
%
% When a node to be pruned has offspring, the pruning procedure invokes
% itself recursively in order to prune the tree from the leaves upward.
% n2, Sr, Sg, and Sb in a node being pruned are always added to the
% corresponding data in that node's parent. This retains the pruned
% node's color characteristics for later averaging.
%
% For each node, n2 pixels exist for which that node represents the
% smallest volume in RGB space containing those pixel's colors. When n2
% > 0 the node will uniquely define a color in the output image. At the
% beginning of reduction, n2 = 0 for all nodes except a the leaves of
% the tree which represent colors present in the input image.
%
% The other pixel count, n1, indicates the total number of colors
% within the cubic volume which the node represents. This includes n1 -
% n2 pixels whose colors should be defined by nodes at a lower level in
% the tree.
%
% The format of the ReduceImageColors method is:
%
% ReduceImageColors(const Image *image,CubeInfo *cube_info)
%
% A description of each parameter follows.
%
% o image: the image.
%
% o cube_info: A pointer to the Cube structure.
%
*/
static void ReduceImageColors(const Image *image,CubeInfo *cube_info)
{
#define ReduceImageTag "Reduce/Image"
MagickBooleanType
proceed;
MagickOffsetType
offset;
unsigned long
span;
cube_info->next_threshold=0.0;
for (span=cube_info->colors; cube_info->colors > cube_info->maximum_colors; )
{
cube_info->pruning_threshold=cube_info->next_threshold;
cube_info->next_threshold=cube_info->root->quantize_error-1;
cube_info->colors=0;
Reduce(image,cube_info,cube_info->root);
offset=(MagickOffsetType) span-cube_info->colors;
proceed=SetImageProgress(image,ReduceImageTag,offset,span-
cube_info->maximum_colors+1);
if (proceed == MagickFalse)
break;
}
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% R e m a p I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% RemapImage() replaces the colors of an image with the closest color from
% a reference image.
%
% The format of the RemapImage method is:
%
% MagickBooleanType RemapImage(const QuantizeInfo *quantize_info,
% Image *image,const Image *remap_image)
%
% A description of each parameter follows:
%
% o quantize_info: Specifies a pointer to an QuantizeInfo structure.
%
% o image: the image.
%
% o remap_image: the reference image.
%
*/
MagickExport MagickBooleanType RemapImage(const QuantizeInfo *quantize_info,
Image *image,const Image *remap_image)
{
CubeInfo
*cube_info;
MagickBooleanType
status;
/*
Initialize color cube.
*/
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",image->filename);
assert(remap_image != (Image *) NULL);
assert(remap_image->signature == MagickSignature);
cube_info=GetCubeInfo(quantize_info,MaxTreeDepth,
quantize_info->number_colors);
if (cube_info == (CubeInfo *) NULL)
ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
image->filename);
status=ClassifyImageColors(cube_info,remap_image,&image->exception);
if (status != MagickFalse)
{
/*
Classify image colors from the reference image.
*/
cube_info->quantize_info->number_colors=cube_info->colors;
status=AssignImageColors(image,cube_info);
}
DestroyCubeInfo(cube_info);
return(status);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% R e m a p I m a g e s %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% RemapImages() replaces the colors of a sequence of images with the
% closest color from a reference image.
%
% The format of the RemapImage method is:
%
% MagickBooleanType RemapImages(const QuantizeInfo *quantize_info,
% Image *images,Image *remap_image)
%
% A description of each parameter follows:
%
% o quantize_info: Specifies a pointer to an QuantizeInfo structure.
%
% o images: the image sequence.
%
% o remap_image: the reference image.
%
*/
MagickExport MagickBooleanType RemapImages(const QuantizeInfo *quantize_info,
Image *images,const Image *remap_image)
{
CubeInfo
*cube_info;
Image
*image;
MagickBooleanType
status;
assert(images != (Image *) NULL);
assert(images->signature == MagickSignature);
if (images->debug != MagickFalse)
(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",images->filename);
image=images;
if (remap_image == (Image *) NULL)
{
/*
Create a global colormap for an image sequence.
*/
status=QuantizeImages(quantize_info,images);
return(status);
}
/*
Classify image colors from the reference image.
*/
cube_info=GetCubeInfo(quantize_info,MaxTreeDepth,
quantize_info->number_colors);
if (cube_info == (CubeInfo *) NULL)
ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
image->filename);
status=ClassifyImageColors(cube_info,remap_image,&image->exception);
if (status != MagickFalse)
{
/*
Classify image colors from the reference image.
*/
cube_info->quantize_info->number_colors=cube_info->colors;
image=images;
for ( ; image != (Image *) NULL; image=GetNextImageInList(image))
{
status=AssignImageColors(image,cube_info);
if (status == MagickFalse)
break;
}
}
DestroyCubeInfo(cube_info);
return(status);
}
/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
% %
% %
% %
% S e t G r a y s c a l e I m a g e %
% %
% %
% %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
% SetGrayscaleImage() converts an image to a PseudoClass grayscale image.
%
% The format of the SetGrayscaleImage method is:
%
% MagickBooleanType SetGrayscaleImage(Image *image)
%
% A description of each parameter follows:
%
% o image: The image.
%
*/
#if defined(__cplusplus) || defined(c_plusplus)
extern "C" {
#endif
static int IntensityCompare(const void *x,const void *y)
{
long
intensity;
PixelPacket
*color_1,
*color_2;
color_1=(PixelPacket *) x;
color_2=(PixelPacket *) y;
intensity=PixelIntensityToQuantum(color_1)-(long)
PixelIntensityToQuantum(color_2);
return(intensity);
}
#if defined(__cplusplus) || defined(c_plusplus)
}
#endif
static MagickBooleanType SetGrayscaleImage(Image *image)
{
ExceptionInfo
*exception;
long
j,
y;
PixelPacket
*colormap;
long
*colormap_index;
register long
i;
MagickBooleanType
status;
CacheView
*image_view;
assert(image != (Image *) NULL);
assert(image->signature == MagickSignature);
if (image->type != GrayscaleType)
(void) TransformImageColorspace(image,GRAYColorspace);
colormap_index=(long *) AcquireQuantumMemory(MaxMap+1,
sizeof(*colormap_index));
if (colormap_index == (long *) NULL)
ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
image->filename);
if (image->storage_class != PseudoClass)
{
ExceptionInfo
*exception;
for (i=0; i <= (long) MaxMap; i++)
colormap_index[i]=(-1);
if (AcquireImageColormap(image,MaxMap+1) == MagickFalse)
ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
image->filename);
image->colors=0;
status=MagickTrue;
exception=(&image->exception);
image_view=AcquireCacheView(image);
#if defined(_OPENMP) && (_OPENMP >= 200203)
#pragma omp parallel for schedule(static,1) shared(status)
#endif
for (y=0; y < (long) image->rows; y++)
{
register IndexPacket
*__restrict indexes;
register long
x;
register const PixelPacket
*__restrict q;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,
exception);
if (q == (PixelPacket *) NULL)
{
status=MagickFalse;
continue;
}
indexes=GetCacheViewAuthenticIndexQueue(image_view);
for (x=0; x < (long) image->columns; x++)
{
register unsigned long
intensity;
intensity=ScaleQuantumToMap(q->red);
if (colormap_index[intensity] < 0)
{
#if defined(_OPENMP) && (_OPENMP >= 200203)
#pragma omp critical (MagickCore_SetGrayscaleImage)
#endif
if (colormap_index[intensity] < 0)
{
colormap_index[intensity]=(long) image->colors;
image->colormap[image->colors]=(*q);
image->colors++;
}
}
indexes[x]=(IndexPacket) colormap_index[intensity];
q++;
}
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
}
image_view=DestroyCacheView(image_view);
}
for (i=0; i < (long) image->colors; i++)
image->colormap[i].opacity=(unsigned short) i;
qsort((void *) image->colormap,image->colors,sizeof(PixelPacket),
IntensityCompare);
colormap=(PixelPacket *) AcquireQuantumMemory(image->colors,
sizeof(*colormap));
if (colormap == (PixelPacket *) NULL)
ThrowBinaryException(ResourceLimitError,"MemoryAllocationFailed",
image->filename);
j=0;
colormap[j]=image->colormap[0];
for (i=0; i < (long) image->colors; i++)
{
if (IsSameColor(image,&colormap[j],&image->colormap[i]) == MagickFalse)
{
j++;
colormap[j]=image->colormap[i];
}
colormap_index[(long) image->colormap[i].opacity]=j;
}
image->colors=(unsigned long) (j+1);
image->colormap=(PixelPacket *) RelinquishMagickMemory(image->colormap);
image->colormap=colormap;
status=MagickTrue;
exception=(&image->exception);
image_view=AcquireCacheView(image);
#if defined(_OPENMP) && (_OPENMP >= 200203)
#pragma omp parallel for schedule(static,1) shared(status)
#endif
for (y=0; y < (long) image->rows; y++)
{
register IndexPacket
*__restrict indexes;
register long
x;
register const PixelPacket
*__restrict q;
if (status == MagickFalse)
continue;
q=GetCacheViewAuthenticPixels(image_view,0,y,image->columns,1,exception);
if (q == (PixelPacket *) NULL)
{
status=MagickFalse;
continue;
}
indexes=GetCacheViewAuthenticIndexQueue(image_view);
for (x=0; x < (long) image->columns; x++)
indexes[x]=(IndexPacket) colormap_index[ScaleQuantumToMap(indexes[x])];
if (SyncCacheViewAuthenticPixels(image_view,exception) == MagickFalse)
status=MagickFalse;
}
image_view=DestroyCacheView(image_view);
colormap_index=(long *) RelinquishMagickMemory(colormap_index);
image->type=GrayscaleType;
if (IsMonochromeImage(image,&image->exception) != MagickFalse)
image->type=BilevelType;
return(status);
}