001 /*
002 Copyright 2006 Jerry Huxtable
003
004 Licensed under the Apache License, Version 2.0 (the "License");
005 you may not use this file except in compliance with the License.
006 You may obtain a copy of the License at
007
008 http://www.apache.org/licenses/LICENSE-2.0
009
010 Unless required by applicable law or agreed to in writing, software
011 distributed under the License is distributed on an "AS IS" BASIS,
012 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 See the License for the specific language governing permissions and
014 limitations under the License.
015 */
016
017 package com.github.sarxos.webcam.util.jh;
018
019 import java.awt.image.BufferedImage;
020 import java.awt.image.WritableRaster;
021
022
023 public class JHGrayFilter extends JHFilter {
024
025 protected boolean canFilterIndexColorModel = true;
026
027 @Override
028 public BufferedImage filter(BufferedImage src, BufferedImage dst) {
029
030 int width = src.getWidth();
031 int height = src.getHeight();
032 int type = src.getType();
033
034 WritableRaster srcRaster = src.getRaster();
035
036 if (dst == null) {
037 dst = createCompatibleDestImage(src, null);
038 }
039
040 WritableRaster dstRaster = dst.getRaster();
041
042 int[] inPixels = new int[width];
043 for (int y = 0; y < height; y++) {
044 if (type == BufferedImage.TYPE_INT_ARGB) {
045 srcRaster.getDataElements(0, y, width, 1, inPixels);
046 for (int x = 0; x < width; x++) {
047 inPixels[x] = filterRGB(inPixels[x]);
048 }
049 dstRaster.setDataElements(0, y, width, 1, inPixels);
050 } else {
051 src.getRGB(0, y, width, 1, inPixels, 0, width);
052 for (int x = 0; x < width; x++) {
053 inPixels[x] = filterRGB(inPixels[x]);
054 }
055 dst.setRGB(0, y, width, 1, inPixels, 0, width);
056 }
057 }
058
059 return dst;
060 }
061
062 private int filterRGB(int rgb) {
063 int a = rgb & 0xff000000;
064 int r = (rgb >> 16) & 0xff;
065 int g = (rgb >> 8) & 0xff;
066 int b = rgb & 0xff;
067 rgb = (r * 77 + g * 151 + b * 28) >> 8; // NTSC luma
068 return a | (rgb << 16) | (rgb << 8) | rgb;
069 }
070 }