001/**
002 *
003 * Copyright (c) 2014, the Railo Company Ltd. All rights reserved.
004 *
005 * This library is free software; you can redistribute it and/or
006 * modify it under the terms of the GNU Lesser General Public
007 * License as published by the Free Software Foundation; either 
008 * version 2.1 of the License, or (at your option) any later version.
009 * 
010 * This library is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
013 * Lesser General Public License for more details.
014 * 
015 * You should have received a copy of the GNU Lesser General Public 
016 * License along with this library.  If not, see <http://www.gnu.org/licenses/>.
017 * 
018 **/
019/*
020*
021
022Licensed under the Apache License, Version 2.0 (the "License");
023you may not use this file except in compliance with the License.
024You may obtain a copy of the License at
025
026   http://www.apache.org/licenses/LICENSE-2.0
027
028Unless required by applicable law or agreed to in writing, software
029distributed under the License is distributed on an "AS IS" BASIS,
030WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
031See the License for the specific language governing permissions and
032limitations under the License.
033*/
034
035package lucee.runtime.img.filter;import java.awt.Rectangle;
036import java.awt.image.BufferedImage;
037
038import lucee.runtime.engine.ThreadLocalPageContext;
039import lucee.runtime.exp.FunctionException;
040import lucee.runtime.exp.PageException;
041import lucee.runtime.img.ImageUtil;
042import lucee.runtime.type.Struct;
043import lucee.runtime.type.util.CollectionUtil;
044
045/**
046 * A filter to perform auto-equalization on an image.
047 */
048public class EqualizeFilter extends WholeImageFilter  implements DynFiltering {
049
050    private int[][] lut;
051
052        public EqualizeFilter() {
053        }
054
055        protected int[] filterPixels( int width, int height, int[] inPixels, Rectangle transformedSpace ) {
056                Histogram histogram = new Histogram(inPixels, width, height, 0, width);
057
058                int i, j;
059
060                if (histogram.getNumSamples() > 0) {
061                        float scale = 255.0f / histogram.getNumSamples();
062                        lut = new int[3][256];
063                        for (i = 0; i < 3; i++) {
064                                lut[i][0] = histogram.getFrequency(i, 0);
065                                for (j = 1; j < 256; j++)
066                                        lut[i][j] = lut[i][j-1] + histogram.getFrequency(i, j);
067                                for (j = 0; j < 256; j++)
068                                        lut[i][j] = Math.round(lut[i][j]*scale);
069                        }
070                } else
071                        lut = null;
072
073                i = 0;
074                for (int y = 0; y < height; y++)
075                        for (int x = 0; x < width; x++) {
076                                inPixels[i] = filterRGB(x, y, inPixels[i]);
077                                i++;
078                        }
079                lut = null;
080                
081                return inPixels;
082        }
083
084        private int filterRGB(int x, int y, int rgb) {
085                if (lut != null) {
086                        int a = rgb & 0xff000000;
087                        int r = lut[Histogram.RED][(rgb >> 16) & 0xff];
088                        int g = lut[Histogram.GREEN][(rgb >> 8) & 0xff];
089                        int b = lut[Histogram.BLUE][rgb & 0xff];
090
091                        return a | (r << 16) | (g << 8) | b;
092                }
093                return rgb;
094        }
095
096        public String toString() {
097                return "Colors/Equalize";
098        }
099        public BufferedImage filter(BufferedImage src, Struct parameters) throws PageException {BufferedImage dst=ImageUtil.createBufferedImage(src);
100                //Object o;
101
102                // check for arguments not supported
103                if(parameters.size()>0) {
104                        throw new FunctionException(ThreadLocalPageContext.get(), "ImageFilter", 3, "parameters", "the parameter"+(parameters.size()>1?"s":"")+" ["+CollectionUtil.getKeyList(parameters,", ")+"] "+(parameters.size()>1?"are":"is")+" not allowed, only the following parameters are supported []");
105                }
106
107                return filter(src, dst);
108        }
109}