| /* |
| * Copyright (c) 2005, 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| package com.sun.imageio.plugins.tiff; |
| |
| import javax.imageio.plugins.tiff.BaselineTIFFTagSet; |
| import javax.imageio.plugins.tiff.TIFFField; |
| |
| public class TIFFYCbCrColorConverter extends TIFFColorConverter { |
| |
| private static final float CODING_RANGE_Y = 255.0f; |
| private static final float CODING_RANGE_CB_CR = 127.0f; |
| |
| private float lumaRed = 0.299f; |
| private float lumaGreen = 0.587f; |
| private float lumaBlue = 0.114f; |
| |
| private float referenceBlackY = 0.0f; |
| private float referenceWhiteY = 255.0f; |
| |
| private float referenceBlackCb = 128.0f; |
| private float referenceWhiteCb = 255.0f; |
| |
| private float referenceBlackCr = 128.0f; |
| private float referenceWhiteCr = 255.0f; |
| |
| public TIFFYCbCrColorConverter(TIFFImageMetadata metadata) { |
| TIFFImageMetadata tmetadata = metadata; |
| |
| TIFFField f = |
| tmetadata.getTIFFField(BaselineTIFFTagSet.TAG_Y_CB_CR_COEFFICIENTS); |
| if (f != null && f.getCount() == 3) { |
| this.lumaRed = f.getAsFloat(0); |
| this.lumaGreen = f.getAsFloat(1); |
| this.lumaBlue = f.getAsFloat(2); |
| } |
| |
| f = |
| tmetadata.getTIFFField(BaselineTIFFTagSet.TAG_REFERENCE_BLACK_WHITE); |
| if (f != null && f.getCount() == 6) { |
| this.referenceBlackY = f.getAsFloat(0); |
| this.referenceWhiteY = f.getAsFloat(1); |
| this.referenceBlackCb = f.getAsFloat(2); |
| this.referenceWhiteCb = f.getAsFloat(3); |
| this.referenceBlackCr = f.getAsFloat(4); |
| this.referenceWhiteCr = f.getAsFloat(5); |
| } |
| } |
| |
| /* |
| The full range component value is converted from the code by: |
| |
| FullRangeValue = (code - ReferenceBlack) * CodingRange |
| / (ReferenceWhite - ReferenceBlack); |
| |
| The code is converted from the full-range component value by: |
| |
| code = (FullRangeValue * (ReferenceWhite - ReferenceBlack) |
| / CodingRange) + ReferenceBlack; |
| |
| */ |
| public void fromRGB(float r, float g, float b, float[] result) { |
| // Convert RGB to full-range YCbCr. |
| float Y = (lumaRed*r + lumaGreen*g + lumaBlue*b); |
| float Cb = (b - Y)/(2 - 2*lumaBlue); |
| float Cr = (r - Y)/(2 - 2*lumaRed); |
| |
| // Convert full-range YCbCr to code. |
| result[0] = Y*(referenceWhiteY - referenceBlackY)/CODING_RANGE_Y + |
| referenceBlackY; |
| result[1] = Cb*(referenceWhiteCb - referenceBlackCb)/CODING_RANGE_CB_CR + |
| referenceBlackCb; |
| result[2] = Cr*(referenceWhiteCr - referenceBlackCr)/CODING_RANGE_CB_CR + |
| referenceBlackCr; |
| } |
| |
| public void toRGB(float x0, float x1, float x2, float[] rgb) { |
| // Convert YCbCr code to full-range YCbCr. |
| float Y = (x0 - referenceBlackY)*CODING_RANGE_Y/ |
| (referenceWhiteY - referenceBlackY); |
| float Cb = (x1 - referenceBlackCb)*CODING_RANGE_CB_CR/ |
| (referenceWhiteCb - referenceBlackCb); |
| float Cr = (x2 - referenceBlackCr)*CODING_RANGE_CB_CR/ |
| (referenceWhiteCr - referenceBlackCr); |
| |
| // Convert YCbCr to RGB. |
| rgb[0] = Cr*(2 - 2*lumaRed) + Y; |
| rgb[2] = Cb*(2 - 2*lumaBlue) + Y; |
| rgb[1] = (Y - lumaBlue*rgb[2] - lumaRed*rgb[0])/lumaGreen; |
| } |
| } |