001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.imaging.formats.tiff.photometricinterpreters; 018 019import java.io.IOException; 020 021import org.apache.commons.imaging.ImageReadException; 022import org.apache.commons.imaging.common.ImageBuilder; 023 024public class PhotometricInterpreterYCbCr extends PhotometricInterpreter { 025 026 public PhotometricInterpreterYCbCr(final int samplesPerPixel, 027 final int[] bitsPerSample, final int predictor, 028 final int width, final int height) { 029 super(samplesPerPixel, bitsPerSample, predictor, width, height); 030 } 031 032 public static int limit(final int value, final int min, final int max) { 033 return Math.min(max, Math.max(min, value)); 034 } 035 036 /** 037 * This method converts a YUV (aka YCbCr) colorspace to a RGB colorspace. 038 * This is handy when trying to reconstruct an image in Java from YCbCr 039 * transmitted data. This routine expects the data to fall in the standard 040 * PC 0..255 range per pixel, with the array dimensions corresponding to the 041 * imageWidth and imageHeight. These variables are either set manually in 042 * the case of a null constructor, or they are automatically calculated from 043 * the image parameter constructor. 044 * 045 * @param Y 046 * The Y component set. 047 * @param Cb 048 * The Cb component set. 049 * @param Cr 050 * The Cr component set. 051 * @return R The R component. 052 */ 053 public static int convertYCbCrtoRGB(final int Y, final int Cb, final int Cr) { 054 final double r1 = (((1.164 * (Y - 16.0))) + (1.596 * (Cr - 128.0))); 055 final double g1 = (((1.164 * (Y - 16.0))) - (0.813 * (Cr - 128.0)) - (0.392 * (Cb - 128.0))); 056 final double b1 = (((1.164 * (Y - 16.0))) + (2.017 * (Cb - 128.0))); 057 058 final int r = limit((int) r1, 0, 255); 059 final int g = limit((int) g1, 0, 255); 060 final int b = limit((int) b1, 0, 255); 061 062 final int alpha = 0xff; 063 return (alpha << 24) | (r << 16) | (g << 8) | (b << 0); 064 } 065 066 @Override 067 public void interpretPixel(final ImageBuilder imageBuilder, final int[] samples, final int x, 068 final int y) throws ImageReadException, IOException { 069 final int Y = samples[0]; 070 final int Cb = samples[1]; 071 final int Cr = samples[2]; 072 final double R = Y + 1.402 * (Cr - 128.0); 073 final double G = Y - 0.34414 * (Cb - 128.0) - 0.71414 * (Cr - 128.0); 074 final double B = Y + 1.772 * (Cb - 128.0); 075 076 final int red = limit((int) R, 0, 255); 077 final int green = limit((int) G, 0, 255); 078 final int blue = limit((int) B, 0, 255); 079 080 final int alpha = 0xff; 081 final int rgb = (alpha << 24) | (red << 16) | (green << 8) | (blue << 0); 082 imageBuilder.setRGB(x, y, rgb); 083 084 } 085}