PhotometricInterpreterYCbCr.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* 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.
*/
package org.apache.commons.imaging.formats.tiff.photometricinterpreters;
import java.io.IOException;
import org.apache.commons.imaging.ImagingException;
import org.apache.commons.imaging.common.ImageBuilder;
public class PhotometricInterpreterYCbCr extends PhotometricInterpreter {
/**
* This method converts a YUV (aka YCbCr) colorspace to a RGB colorspace. This is handy when trying to reconstruct an image in Java from YCbCr transmitted
* data. This routine expects the data to fall in the standard PC 0..255 range per pixel, with the array dimensions corresponding to the imageWidth and
* imageHeight. These variables are either set manually in the case of a null constructor, or they are automatically calculated from the image parameter
* constructor.
*
* @param y The Y component set.
* @param cb The Cb component set.
* @param cr The Cr component set.
* @return R The R component.
*/
public static int convertYCbCrtoRGB(final int y, final int cb, final int cr) {
final double r1 = 1.164 * (y - 16.0) + 1.596 * (cr - 128.0);
final double g1 = 1.164 * (y - 16.0) - 0.813 * (cr - 128.0) - 0.392 * (cb - 128.0);
final double b1 = 1.164 * (y - 16.0) + 2.017 * (cb - 128.0);
final int r = limit((int) r1, 0, 255);
final int g = limit((int) g1, 0, 255);
final int b = limit((int) b1, 0, 255);
final int alpha = 0xff;
return alpha << 24 | r << 16 | g << 8 | b << 0;
}
public static int limit(final int value, final int min, final int max) {
return Math.min(max, Math.max(min, value));
}
public PhotometricInterpreterYCbCr(final int samplesPerPixel, final int[] bitsPerSample, final int predictor, final int width, final int height) {
super(samplesPerPixel, bitsPerSample, predictor, width, height);
}
@Override
public void interpretPixel(final ImageBuilder imageBuilder, final int[] samples, final int x, final int y) throws ImagingException, IOException {
final int Y = samples[0];
final int cb = samples[1];
final int cr = samples[2];
final double r = Y + 1.402 * (cr - 128.0);
final double g = Y - 0.34414 * (cb - 128.0) - 0.71414 * (cr - 128.0);
final double b = Y + 1.772 * (cb - 128.0);
final int red = limit((int) r, 0, 255);
final int green = limit((int) g, 0, 255);
final int blue = limit((int) b, 0, 255);
final int alpha = 0xff;
final int rgb = alpha << 24 | red << 16 | green << 8 | blue << 0;
imageBuilder.setRgb(x, y, rgb);
}
}