| /* YCbCr_ColorSpace.java -- |
| Copyright (C) 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| package gnu.javax.imageio.jpeg; |
| |
| import java.awt.color.ColorSpace; |
| |
| public class YCbCr_ColorSpace extends ColorSpace { |
| public YCbCr_ColorSpace() { |
| super(ColorSpace.TYPE_YCbCr, 3); |
| } |
| |
| public float[] fromCIEXYZ(float[] data) { |
| return(new float[data.length]); |
| } |
| |
| public float[] toCIEXYZ(float[] data) { |
| return(new float[data.length]); |
| } |
| |
| public float[] fromRGB(float[] data) { |
| return(new float[data.length]); |
| } |
| |
| /* YCbCr to RGB range 0 to 1 */ |
| public float[] toRGB(float[] data) { |
| float[] dest = new float[3]; |
| |
| data[0] *= 255; |
| data[1] *= 255; |
| data[2] *= 255; |
| |
| dest[0] = (float)data[0] + (float)1.402*((float)data[2]-(float)128); |
| dest[1] = (float)data[0] - (float)0.34414*((float)data[1]-(float)128) - (float)0.71414*((float)data[2]-(float)128); |
| dest[2] = (float)data[0] + (float)1.772*((float)data[1]-(float)128); |
| |
| dest[0] /= 255; |
| dest[1] /= 255; |
| dest[2] /= 255; |
| |
| //dest[0] = ((float)1.164*((float)data[0]*(float)255 - (float)16) + (float)1.596*((float)data[2]*(float)255 - (float)128))/(float)255; |
| //dest[1] = ((float)1.164*((float)data[0]*(float)255 - (float)16) - (float)0.813*((float)data[2]*(float)255 - (float)128) - (float)0.392*(data[1]*255 - 128))/(float)255; |
| //dest[2] = ((float)1.164*((float)data[0]*(float)255 - (float)16) + (float)2.017*((float)data[1]*(float)255 - (float)128))/(float)255; |
| |
| //System.err.println("toRGB values received: 0: "+data[0]+" 1: "+data[1]+" 2: "+data[2]+" sent: 0: "+dest[0]+" 1: "+dest[1]+" 2: "+dest[2]); |
| if(dest[0] < (float)0) |
| dest[0] = 0; |
| if(dest[1] < (float)0) |
| dest[1] = 0; |
| if(dest[2] < (float)0) |
| dest[2] = 0; |
| |
| if(dest[0] > (float)1) |
| dest[0] = 1; |
| if(dest[1] > (float)1) |
| dest[1] = 1; |
| if(dest[2] > (float)1) |
| dest[2] = 1; |
| |
| |
| return(dest); |
| } |
| |
| /* RGB to YCbCr range 0-255 */ |
| public static float[] toYCbCr(float[] data) { |
| float[] dest = new float[3]; |
| //dest[0] = (float)0.257*data[0] + (float)0.504*data[1] + (float)0.098*data[2] + 16; |
| //dest[1] = (float)-0.148*data[0] - (float)0.291*data[1] + (float)0.439*data[2] + 128; |
| //dest[2] = (float)0.439*data[0] - (float)0.368*data[1] - (float)0.071*data[2] + 128; |
| |
| dest[0] = (float)((0.299 * (float)data[0] + 0.587 * (float)data[1] + 0.114 * (float)data[2])); |
| dest[1] = 128 + (float)((-0.16874 * (float)data[0] - 0.33126 * (float)data[1] + 0.5 * (float)data[2])); |
| dest[2] = 128 + (float)((0.5 * (float)data[0] - 0.41869 * (float)data[1] - 0.08131 * (float)data[2])); |
| |
| |
| return(dest); |
| |
| } |
| } |