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.image.BufferedImage;
036
037import lucee.runtime.engine.ThreadLocalPageContext;
038import lucee.runtime.exp.FunctionException;
039import lucee.runtime.exp.PageException;
040import lucee.runtime.img.ImageUtil;
041import lucee.runtime.type.KeyImpl;
042import lucee.runtime.type.Struct;
043import lucee.runtime.type.util.CollectionUtil;
044
045
046
047/**
048 * A filter which changes the exposure of an image.
049 */
050public class ExposureFilter extends TransferFilter  implements DynFiltering {
051
052        private float exposure = 1.0f;
053
054        protected float transferFunction( float f ) {
055                return 1 - (float)Math.exp(-f * exposure);
056        }
057
058    /**
059     * Set the exposure level.
060     * @param exposure the exposure level
061     * @min-value 0
062     * @max-value 5+
063     * @see #getExposure
064     */
065        public void setExposure(float exposure) {
066                this.exposure = exposure;
067                initialized = false;
068        }
069        
070    /**
071     * Get the exposure level.
072     * @return the exposure level
073     * @see #setExposure
074     */
075        public float getExposure() {
076                return exposure;
077        }
078
079        public String toString() {
080                return "Colors/Exposure...";
081        }
082
083        public BufferedImage filter(BufferedImage src, Struct parameters) throws PageException {BufferedImage dst=ImageUtil.createBufferedImage(src);
084                Object o;
085                if((o=parameters.removeEL(KeyImpl.init("Exposure")))!=null)setExposure(ImageFilterUtil.toFloatValue(o,"Exposure"));
086                if((o=parameters.removeEL(KeyImpl.init("Dimensions")))!=null){
087                        int[] dim=ImageFilterUtil.toDimensions(o,"Dimensions");
088                        setDimensions(dim[0],dim[1]);
089                }
090
091                // check for arguments not supported
092                if(parameters.size()>0) {
093                        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 [Exposure, Dimensions]");
094                }
095
096                return filter(src, dst);
097        }
098}
099