001 /* 002 * 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 railo.runtime.img.filter;import java.awt.image.BufferedImage; 018 019 import railo.runtime.engine.ThreadLocalPageContext; 020 import railo.runtime.exp.FunctionException; 021 import railo.runtime.exp.PageException; 022 import railo.runtime.img.ImageUtil; 023 import railo.runtime.type.KeyImpl; 024 import railo.runtime.type.Struct; 025 import railo.runtime.type.util.CollectionUtil; 026 027 028 029 /** 030 * A filter to change the brightness and contrast of an image. 031 */ 032 public class ContrastFilter extends TransferFilter implements DynFiltering { 033 034 private float brightness = 1.0f; 035 private float contrast = 1.0f; 036 037 protected float transferFunction( float f ) { 038 f = f*brightness; 039 f = (f-0.5f)*contrast+0.5f; 040 return f; 041 } 042 043 /** 044 * Set the filter brightness. 045 * @param brightness the brightness in the range 0 to 1 046 * @min-value 0 047 * @max-value 0 048 * @see #getBrightness 049 */ 050 public void setBrightness(float brightness) { 051 this.brightness = brightness; 052 initialized = false; 053 } 054 055 /** 056 * Get the filter brightness. 057 * @return the brightness in the range 0 to 1 058 * @see #setBrightness 059 */ 060 public float getBrightness() { 061 return brightness; 062 } 063 064 /** 065 * Set the filter contrast. 066 * @param contrast the contrast in the range 0 to 1 067 * @min-value 0 068 * @max-value 0 069 * @see #getContrast 070 */ 071 public void setContrast(float contrast) { 072 this.contrast = contrast; 073 initialized = false; 074 } 075 076 /** 077 * Get the filter contrast. 078 * @return the contrast in the range 0 to 1 079 * @see #setContrast 080 */ 081 public float getContrast() { 082 return contrast; 083 } 084 085 public String toString() { 086 return "Colors/Contrast..."; 087 } 088 089 public BufferedImage filter(BufferedImage src, Struct parameters) throws PageException {BufferedImage dst=ImageUtil.createBufferedImage(src); 090 Object o; 091 if((o=parameters.removeEL(KeyImpl.init("Brightness")))!=null)setBrightness(ImageFilterUtil.toFloatValue(o,"Brightness")); 092 if((o=parameters.removeEL(KeyImpl.init("Contrast")))!=null)setContrast(ImageFilterUtil.toFloatValue(o,"Contrast")); 093 if((o=parameters.removeEL(KeyImpl.init("Dimensions")))!=null){ 094 int[] dim=ImageFilterUtil.toDimensions(o,"Dimensions"); 095 setDimensions(dim[0],dim[1]); 096 } 097 098 // check for arguments not supported 099 if(parameters.size()>0) { 100 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]"); 101 } 102 103 return filter(src, dst); 104 } 105 } 106