Modules/rgbimgmodule.c

/*
 *   	fastimg -
 *		Faster reading and writing of image files.
 *
 *      This code should work on machines with any byte order.
 *
 *	Could someone make this run real fast using multiple processors 
 *	or how about using memory mapped files to speed it up?
 *
 *				Paul Haeberli - 1991
 *
 *	Changed to return sizes.
 *				Sjoerd Mullender - 1993
 *	Changed to incorporate into Python.
 *				Sjoerd Mullender - 1993
 */
#include "Python.h"

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <string.h>

/*
 *	from image.h
 *
 */
typedef struct {
	unsigned short	imagic;		/* stuff saved on disk . . */
	unsigned short 	type;
	unsigned short 	dim;
	unsigned short 	xsize;
	unsigned short 	ysize;
	unsigned short 	zsize;
	unsigned long 	min;
	unsigned long 	max;
	unsigned long	wastebytes;	
	char 		name[80];
	unsigned long	colormap;

	long 		file;		/* stuff used in core only */
	unsigned short 	flags;
	short		dorev;
	short		x;
	short		y;
	short		z;
	short		cnt;
	unsigned short	*ptr;
	unsigned short	*base;
	unsigned short	*tmpbuf;
	unsigned long	offset;
	unsigned long	rleend;		/* for rle images */
	unsigned long	*rowstart;	/* for rle images */
	long		*rowsize;	/* for rle images */
} IMAGE;

#define IMAGIC 	0732

#define TYPEMASK		0xff00
#define BPPMASK			0x00ff
#define ITYPE_VERBATIM		0x0000
#define ITYPE_RLE		0x0100
#define ISRLE(type)		(((type) & 0xff00) == ITYPE_RLE)
#define ISVERBATIM(type)	(((type) & 0xff00) == ITYPE_VERBATIM)
#define BPP(type)		((type) & BPPMASK)
#define RLE(bpp)		(ITYPE_RLE | (bpp))
#define VERBATIM(bpp)		(ITYPE_VERBATIM | (bpp))
/*
 *	end of image.h stuff
 *
 */

#define RINTLUM (79)
#define GINTLUM (156)
#define BINTLUM (21)

#define ILUM(r,g,b)     ((int)(RINTLUM*(r)+GINTLUM*(g)+BINTLUM*(b))>>8)

#define OFFSET_R	3	/* this is byte order dependent */
#define OFFSET_G	2
#define OFFSET_B	1
#define OFFSET_A	0

#define CHANOFFSET(z)	(3-(z))	/* this is byte order dependent */

static void expandrow Py_PROTO((unsigned char *, unsigned char *, int));
static void setalpha Py_PROTO((unsigned char *, int));
static void copybw Py_PROTO((long *, int));
static void interleaverow Py_PROTO((unsigned char*, unsigned char*, int, int));
static int compressrow Py_PROTO((unsigned char *, unsigned char *, int, int));
static void lumrow Py_PROTO((unsigned char *, unsigned char *, int));

#ifdef ADD_TAGS
#define TAGLEN	(5)
#else
#define TAGLEN	(0)
#endif

static PyObject *ImgfileError;

static int reverse_order;

#ifdef ADD_TAGS
/*
 *	addlongimgtag - 
 *		this is used to extract image data from core dumps.
 *
 */
addlongimgtag(dptr,xsize,ysize)
	unsigned long *dptr;
int xsize, ysize;
{
	dptr = dptr+(xsize*ysize);
	dptr[0] = 0x12345678;
	dptr[1] = 0x59493333;
	dptr[2] = 0x69434222;
	dptr[3] = xsize;
	dptr[4] = ysize;
}
#endif

/*
 *	byte order independent read/write of shorts and longs.
 *
 */
static unsigned short getshort(inf)
	FILE *inf;
{
	unsigned char buf[2];

	fread(buf,2,1,inf);
	return (buf[0]<<8)+(buf[1]<<0);
}

static unsigned long getlong(inf)
	FILE *inf;
{
	unsigned char buf[4];

	fread(buf,4,1,inf);
	return (buf[0]<<24)+(buf[1]<<16)+(buf[2]<<8)+(buf[3]<<0);
}

static void putshort(outf,val)
	FILE *outf;
unsigned short val;
{
	unsigned char buf[2];

	buf[0] = (val>>8);
	buf[1] = (val>>0);
	fwrite(buf,2,1,outf);
}

static int putlong(outf,val)
	FILE *outf;
unsigned long val;
{
	unsigned char buf[4];

	buf[0] = (val>>24);
	buf[1] = (val>>16);
	buf[2] = (val>>8);
	buf[3] = (val>>0);
	return fwrite(buf,4,1,outf);
}

static void readheader(inf,image)
	FILE *inf;
IMAGE *image;
{
	memset(image,0,sizeof(IMAGE));
	image->imagic = getshort(inf);
	image->type = getshort(inf);
	image->dim = getshort(inf);
	image->xsize = getshort(inf);
	image->ysize = getshort(inf);
	image->zsize = getshort(inf);
}

static int writeheader(outf,image)
	FILE *outf;
IMAGE *image;
{
	IMAGE t;

	memset(&t,0,sizeof(IMAGE));
	fwrite(&t,sizeof(IMAGE),1,outf);
	fseek(outf,0,SEEK_SET);
	putshort(outf,image->imagic);
	putshort(outf,image->type);
	putshort(outf,image->dim);
	putshort(outf,image->xsize);
	putshort(outf,image->ysize);
	putshort(outf,image->zsize);
	putlong(outf,image->min);
	putlong(outf,image->max);
	putlong(outf,0);
	return fwrite("no name",8,1,outf);
}

static int writetab(outf,tab,len)
	FILE *outf;
/*unsigned*/ long *tab;
int len;
{
	int r = 0;

	while(len) {
		r = putlong(outf,*tab++);
		len -= 4;
	}
	return r;
}

static void readtab(inf,tab,len)
	FILE *inf;
/*unsigned*/ long *tab;
int len;
{
	while(len) {
		*tab++ = getlong(inf);
		len -= 4;
	}
}

/*
 *	sizeofimage - 
 *		return the xsize and ysize of an iris image file.
 *
 */
static PyObject *
sizeofimage(self, args)
	PyObject *self, *args;
{
	char *name;
	IMAGE image;
	FILE *inf;

	if (!PyArg_Parse(args, "s", &name))
		return NULL;

	inf = fopen(name,"r");
	if(!inf) {
		PyErr_SetString(ImgfileError, "can't open image file");
		return NULL;
	}
	readheader(inf,&image);
	fclose(inf);
	if(image.imagic != IMAGIC) {
		PyErr_SetString(ImgfileError,
				"bad magic number in image file");
		return NULL;
	}
	return Py_BuildValue("(ii)", image.xsize, image.ysize);
}

/*
 *	longimagedata - 
 *		read in a B/W RGB or RGBA iris image file and return a 
 *	pointer to an array of longs.
 *
 */
static PyObject *
longimagedata(self, args)
	PyObject *self, *args;
{
	char *name;
	unsigned char *base, *lptr;
	unsigned char *rledat, *verdat;
	long *starttab, *lengthtab;
	FILE *inf;
	IMAGE image;
	int y, z, tablen;
	int xsize, ysize, zsize;
	int bpp, rle, cur, badorder;
	int rlebuflen;
	PyObject *rv;

	if (!PyArg_Parse(args, "s", &name))
		return NULL;

	inf = fopen(name,"r");
	if(!inf) {
		PyErr_SetString(ImgfileError,"can't open image file");
		return NULL;
	}
	readheader(inf,&image);
	if(image.imagic != IMAGIC) {
		PyErr_SetString(ImgfileError,"bad magic number in image file");
		fclose(inf);
		return NULL;
	}
	rle = ISRLE(image.type);
	bpp = BPP(image.type);
	if(bpp != 1 ) {
		PyErr_SetString(ImgfileError,
				"image must have 1 byte per pix chan");
		fclose(inf);
		return NULL;
	}
	xsize = image.xsize;
	ysize = image.ysize;
	zsize = image.zsize;
	if(rle) {
		tablen = ysize*zsize*sizeof(long);
		starttab = (long *)malloc(tablen);
		lengthtab = (long *)malloc(tablen);
		rlebuflen = 1.05*xsize+10;
		rledat = (unsigned char *)malloc(rlebuflen);
		fseek(inf,512,SEEK_SET);
		readtab(inf,starttab,tablen);
		readtab(inf,lengthtab,tablen);

/* check data order */
		cur = 0;
		badorder = 0;
		for(y=0; y<ysize; y++) {
			for(z=0; z<zsize; z++) {
				if(starttab[y+z*ysize]<cur) {
					badorder = 1;
					break;
				}
				cur = starttab[y+z*ysize];
			}
			if(badorder) 
				break;
		}

		fseek(inf,512+2*tablen,SEEK_SET);
		cur = 512+2*tablen;
		rv = PyString_FromStringAndSize((char *) 0,
					 (xsize*ysize+TAGLEN)*sizeof(long));
		if (rv == NULL) {
			fclose(inf);
			free(lengthtab);
			free(starttab);
			free(rledat);
			return NULL;
		}
		base = (unsigned char *) PyString_AsString(rv);
#ifdef ADD_TAGS
		addlongimgtag(base,xsize,ysize);
#endif
		if(badorder) {
			for(z=0; z<zsize; z++) {
				lptr = base;
				if (reverse_order)
					lptr += (ysize - 1) * xsize
						* sizeof(unsigned long);
				for(y=0; y<ysize; y++) {
					if(cur != starttab[y+z*ysize]) {
						fseek(inf,starttab[y+z*ysize],
						      SEEK_SET);
						cur = starttab[y+z*ysize];
					}
					if(lengthtab[y+z*ysize]>rlebuflen) {
						PyErr_SetString(ImgfileError,
					     "rlebuf is too small - bad poop");
						fclose(inf);
						Py_DECREF(rv);
						free(rledat);
						free(starttab);
						free(lengthtab);
						return NULL;
					}
					fread(rledat,lengthtab[y+z*ysize],
					      1,inf);
					cur += lengthtab[y+z*ysize];
					expandrow(lptr,rledat,3-z);
					if (reverse_order)
						lptr -= xsize
						      * sizeof(unsigned long);
					else
						lptr += xsize
						      * sizeof(unsigned long);
				}
			}
		} else {
			lptr = base;
			if (reverse_order)
				lptr += (ysize - 1) * xsize
					* sizeof(unsigned long);
			for(y=0; y<ysize; y++) {
				for(z=0; z<zsize; z++) {
					if(cur != starttab[y+z*ysize]) {
						fseek(inf,starttab[y+z*ysize],
						      SEEK_SET);
						cur = starttab[y+z*ysize];
					}
					fread(rledat,lengthtab[y+z*ysize],
					      1,inf);
					cur += lengthtab[y+z*ysize];
					expandrow(lptr,rledat,3-z);
				}
				if (reverse_order)
					lptr -= xsize * sizeof(unsigned long);
				else
					lptr += xsize * sizeof(unsigned long);
			}
		}
		if(zsize == 3) 
			setalpha(base,xsize*ysize);
		else if(zsize<3) 
			copybw((long *) base,xsize*ysize);
		fclose(inf);
		free(starttab);
		free(lengthtab);
		free(rledat);
		return rv;
	} else {
		rv = PyString_FromStringAndSize((char *) 0,
					   (xsize*ysize+TAGLEN)*sizeof(long));
		if (rv == NULL) {
			fclose(inf);
			return NULL;
		}
		base = (unsigned char *) PyString_AsString(rv);
#ifdef ADD_TAGS
		addlongimgtag(base,xsize,ysize);
#endif
		verdat = (unsigned char *)malloc(xsize);
		fseek(inf,512,SEEK_SET);
		for(z=0; z<zsize; z++) {
			lptr = base;
			if (reverse_order)
				lptr += (ysize - 1) * xsize
				        * sizeof(unsigned long);
			for(y=0; y<ysize; y++) {
				fread(verdat,xsize,1,inf);
				interleaverow(lptr,verdat,3-z,xsize);
				if (reverse_order)
					lptr -= xsize * sizeof(unsigned long);
				else
					lptr += xsize * sizeof(unsigned long);
			}
		}
		if(zsize == 3) 
			setalpha(base,xsize*ysize);
		else if(zsize<3) 
			copybw((long *) base,xsize*ysize);
		fclose(inf);
		free(verdat);
		return rv;
	}
}

/* static utility functions for longimagedata */

static void interleaverow(lptr,cptr,z,n)
	unsigned char *lptr, *cptr;
int z, n;
{
	lptr += z;
	while(n--) {
		*lptr = *cptr++;
		lptr += 4;
	}
}

static void copybw(lptr,n)
	long *lptr;
int n;
{
	while(n>=8) {
		lptr[0] = 0xff000000+(0x010101*(lptr[0]&0xff));
		lptr[1] = 0xff000000+(0x010101*(lptr[1]&0xff));
		lptr[2] = 0xff000000+(0x010101*(lptr[2]&0xff));
		lptr[3] = 0xff000000+(0x010101*(lptr[3]&0xff));
		lptr[4] = 0xff000000+(0x010101*(lptr[4]&0xff));
		lptr[5] = 0xff000000+(0x010101*(lptr[5]&0xff));
		lptr[6] = 0xff000000+(0x010101*(lptr[6]&0xff));
		lptr[7] = 0xff000000+(0x010101*(lptr[7]&0xff));
		lptr += 8;
		n-=8;
	}
	while(n--) {
		*lptr = 0xff000000+(0x010101*(*lptr&0xff));
		lptr++;
	}
}

static void setalpha(lptr,n)
	unsigned char *lptr;
{
	while(n>=8) {
		lptr[0*4] = 0xff;
		lptr[1*4] = 0xff;
		lptr[2*4] = 0xff;
		lptr[3*4] = 0xff;
		lptr[4*4] = 0xff;
		lptr[5*4] = 0xff;
		lptr[6*4] = 0xff;
		lptr[7*4] = 0xff;
		lptr += 4*8;
		n -= 8;
	}
	while(n--) {
		*lptr = 0xff;
		lptr += 4;
	}
}

static void expandrow(optr,iptr,z)
	unsigned char *optr, *iptr;
int z;
{
	unsigned char pixel, count;

	optr += z;
	while(1) {
		pixel = *iptr++;
		if ( !(count = (pixel & 0x7f)) )
			return;
		if(pixel & 0x80) {
			while(count>=8) {
				optr[0*4] = iptr[0];
				optr[1*4] = iptr[1];
				optr[2*4] = iptr[2];
				optr[3*4] = iptr[3];
				optr[4*4] = iptr[4];
				optr[5*4] = iptr[5];
				optr[6*4] = iptr[6];
				optr[7*4] = iptr[7];
				optr += 8*4;
				iptr += 8;
				count -= 8;
			}
			while(count--) {
				*optr = *iptr++;
				optr+=4;
			}
		} else {
			pixel = *iptr++;
			while(count>=8) {
				optr[0*4] = pixel;
				optr[1*4] = pixel;
				optr[2*4] = pixel;
				optr[3*4] = pixel;
				optr[4*4] = pixel;
				optr[5*4] = pixel;
				optr[6*4] = pixel;
				optr[7*4] = pixel;
				optr += 8*4;
				count -= 8;
			}
			while(count--) {
				*optr = pixel;
				optr+=4;
			}
		}
	}
}

/*
 *	longstoimage -
 *		copy an array of longs to an iris image file.  Each long
 *	represents one pixel.  xsize and ysize specify the dimensions of
 *	the pixel array.  zsize specifies what kind of image file to
 *	write out.  if zsize is 1, the luminance of the pixels are
 *	calculated, and a sinlge channel black and white image is saved.
 *	If zsize is 3, an RGB image file is saved.  If zsize is 4, an
 *	RGBA image file is saved.
 *
 */
static PyObject *
longstoimage(self, args)
	PyObject *self, *args;
{
	unsigned char *lptr;
	char *name;
	int xsize, ysize, zsize;
	FILE *outf;
	IMAGE image;
	int tablen, y, z, pos, len;
	long *starttab, *lengthtab;
	unsigned char *rlebuf;
	unsigned char *lumbuf;
	int rlebuflen, goodwrite;

	if (!PyArg_Parse(args, "(s#iiis)", &lptr, &len, &xsize, &ysize, &zsize,
			 &name))
		return NULL;

	goodwrite = 1;
	outf = fopen(name,"w");
	if(!outf) {
		PyErr_SetString(ImgfileError,"can't open output file");
		return NULL;
	}
	tablen = ysize*zsize*sizeof(long);

	starttab = (long *)malloc(tablen);
	lengthtab = (long *)malloc(tablen);
	rlebuflen = 1.05*xsize+10;
	rlebuf = (unsigned char *)malloc(rlebuflen);
	lumbuf = (unsigned char *)malloc(xsize*sizeof(long));

	memset(&image,0,sizeof(IMAGE));
	image.imagic = IMAGIC; 
	image.type = RLE(1);
	if(zsize>1)
		image.dim = 3;
	else
		image.dim = 2;
	image.xsize = xsize;
	image.ysize = ysize;
	image.zsize = zsize;
	image.min = 0;
	image.max = 255;
	goodwrite *= writeheader(outf,&image);
	fseek(outf,512+2*tablen,SEEK_SET);
	pos = 512+2*tablen;
	if (reverse_order)
		lptr += (ysize - 1) * xsize * sizeof(unsigned long);
	for(y=0; y<ysize; y++) {
		for(z=0; z<zsize; z++) {
			if(zsize == 1) {
				lumrow(lptr,lumbuf,xsize);
				len = compressrow(lumbuf,rlebuf,CHANOFFSET(z),
						  xsize);
			} else {
				len = compressrow(lptr,rlebuf,CHANOFFSET(z),
						  xsize);
			}
			if(len>rlebuflen) {
				PyErr_SetString(ImgfileError,
					   "rlebuf is too small - bad poop");
				free(starttab);
				free(lengthtab);
				free(rlebuf);
				free(lumbuf);
				fclose(outf);
				return NULL;
			}
			goodwrite *= fwrite(rlebuf,len,1,outf);
			starttab[y+z*ysize] = pos;
			lengthtab[y+z*ysize] = len;
			pos += len;
		}
		if (reverse_order)
			lptr -= xsize * sizeof(unsigned long);
		else
			lptr += xsize * sizeof(unsigned long);
	}

	fseek(outf,512,SEEK_SET);
	goodwrite *= writetab(outf,starttab,tablen);
	goodwrite *= writetab(outf,lengthtab,tablen);
	free(starttab);
	free(lengthtab);
	free(rlebuf);
	free(lumbuf);
	fclose(outf);
	if(goodwrite) {
		Py_INCREF(Py_None);
		return Py_None;
	} else {
		PyErr_SetString(ImgfileError,"not enough space for image!!");
		return NULL;
	}
}

/* static utility functions for longstoimage */

static void lumrow(rgbptr,lumptr,n) 
	unsigned char *rgbptr, *lumptr;
int n;
{
	lumptr += CHANOFFSET(0);
	while(n--) {
		*lumptr = ILUM(rgbptr[OFFSET_R],rgbptr[OFFSET_G],
			       rgbptr[OFFSET_B]);
		lumptr += 4;
		rgbptr += 4;
	}
}

static int compressrow(lbuf,rlebuf,z,cnt)
	unsigned char *lbuf, *rlebuf;
int z, cnt;
{
	unsigned char *iptr, *ibufend, *sptr, *optr;
	short todo, cc;							
	long count;

	lbuf += z;
	iptr = lbuf;
	ibufend = iptr+cnt*4;
	optr = rlebuf;

	while(iptr<ibufend) {
		sptr = iptr;
		iptr += 8;
		while((iptr<ibufend)&& ((iptr[-8]!=iptr[-4])
					||(iptr[-4]!=iptr[0])))
			iptr+=4;
		iptr -= 8;
		count = (iptr-sptr)/4;
		while(count) {
			todo = count>126 ? 126:count;
			count -= todo;
			*optr++ = 0x80|todo;
			while(todo>8) {
				optr[0] = sptr[0*4];
				optr[1] = sptr[1*4];
				optr[2] = sptr[2*4];
				optr[3] = sptr[3*4];
				optr[4] = sptr[4*4];
				optr[5] = sptr[5*4];
				optr[6] = sptr[6*4];
				optr[7] = sptr[7*4];
				optr += 8;
				sptr += 8*4;
				todo -= 8;
			}
			while(todo--) {
				*optr++ = *sptr;
				sptr += 4;
			}
		}
		sptr = iptr;
		cc = *iptr;
		iptr += 4;
		while( (iptr<ibufend) && (*iptr == cc) )
			iptr += 4;
		count = (iptr-sptr)/4;
		while(count) {
			todo = count>126 ? 126:count;
			count -= todo;
			*optr++ = todo;
			*optr++ = cc;
		}
	}
	*optr++ = 0;
	return optr - (unsigned char *)rlebuf;
}

static PyObject *
ttob(self, args)
	PyObject *self;
PyObject *args;
{
	int order, oldorder;

	if (!PyArg_Parse(args, "i", &order))
		return NULL;
	oldorder = reverse_order;
	reverse_order = order;
	return PyInt_FromLong(oldorder);
}

static PyMethodDef rgbimg_methods[] = {
	{"sizeofimage",	sizeofimage},
	{"longimagedata",	longimagedata},
	{"longstoimage",	longstoimage},
	{"ttob",		ttob},
	{NULL, NULL}		/* sentinel */
};

void
initrgbimg()
{
	PyObject *m, *d;
	m = Py_InitModule("rgbimg", rgbimg_methods);
	d = PyModule_GetDict(m);
	ImgfileError = PyString_FromString("rgbimg.error");
	if (ImgfileError == NULL
	    || PyDict_SetItemString(d, "error", ImgfileError))
		Py_FatalError("can't define rgbimg.error");
}