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 to change the brightness and contrast of an image. 049 */ 050public class ContrastFilter extends TransferFilter implements DynFiltering { 051 052 private float brightness = 1.0f; 053 private float contrast = 1.0f; 054 055 protected float transferFunction( float f ) { 056 f = f*brightness; 057 f = (f-0.5f)*contrast+0.5f; 058 return f; 059 } 060 061 /** 062 * Set the filter brightness. 063 * @param brightness the brightness in the range 0 to 1 064 * @min-value 0 065 * @max-value 0 066 * @see #getBrightness 067 */ 068 public void setBrightness(float brightness) { 069 this.brightness = brightness; 070 initialized = false; 071 } 072 073 /** 074 * Get the filter brightness. 075 * @return the brightness in the range 0 to 1 076 * @see #setBrightness 077 */ 078 public float getBrightness() { 079 return brightness; 080 } 081 082 /** 083 * Set the filter contrast. 084 * @param contrast the contrast in the range 0 to 1 085 * @min-value 0 086 * @max-value 0 087 * @see #getContrast 088 */ 089 public void setContrast(float contrast) { 090 this.contrast = contrast; 091 initialized = false; 092 } 093 094 /** 095 * Get the filter contrast. 096 * @return the contrast in the range 0 to 1 097 * @see #setContrast 098 */ 099 public float getContrast() { 100 return contrast; 101 } 102 103 public String toString() { 104 return "Colors/Contrast..."; 105 } 106 107 public BufferedImage filter(BufferedImage src, Struct parameters) throws PageException {BufferedImage dst=ImageUtil.createBufferedImage(src); 108 Object o; 109 if((o=parameters.removeEL(KeyImpl.init("Brightness")))!=null)setBrightness(ImageFilterUtil.toFloatValue(o,"Brightness")); 110 if((o=parameters.removeEL(KeyImpl.init("Contrast")))!=null)setContrast(ImageFilterUtil.toFloatValue(o,"Contrast")); 111 if((o=parameters.removeEL(KeyImpl.init("Dimensions")))!=null){ 112 int[] dim=ImageFilterUtil.toDimensions(o,"Dimensions"); 113 setDimensions(dim[0],dim[1]); 114 } 115 116 // check for arguments not supported 117 if(parameters.size()>0) { 118 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 [Brightness, Contrast, Dimensions]"); 119 } 120 121 return filter(src, dst); 122 } 123} 124