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 which unpremultiplies an image's alpha. 031 * Note: this does not change the image type of the BufferedImage 032 */ 033 public class UnpremultiplyFilter extends PointFilter implements DynFiltering { 034 035 public UnpremultiplyFilter() { 036 } 037 038 public int filterRGB(int x, int y, int rgb) { 039 int a = (rgb >> 24) & 0xff; 040 int r = (rgb >> 16) & 0xff; 041 int g = (rgb >> 8) & 0xff; 042 int b = rgb & 0xff; 043 if ( a == 0 || a == 255 ) 044 return rgb; 045 046 float f = 255.0f / a; 047 r *= f; 048 g *= f; 049 b *= f; 050 if ( r > 255 ) 051 r = 255; 052 if ( g > 255 ) 053 g = 255; 054 if ( b > 255 ) 055 b = 255; 056 return (a << 24) | (r << 16) | (g << 8) | b; 057 } 058 059 public String toString() { 060 return "Alpha/Unpremultiply"; 061 } 062 public BufferedImage filter(BufferedImage src, Struct parameters) throws PageException {BufferedImage dst=ImageUtil.createBufferedImage(src); 063 Object o; 064 if((o=parameters.removeEL(KeyImpl.init("Dimensions")))!=null){ 065 int[] dim=ImageFilterUtil.toDimensions(o,"Dimensions"); 066 setDimensions(dim[0],dim[1]); 067 } 068 069 // check for arguments not supported 070 if(parameters.size()>0) { 071 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 [Dimensions]"); 072 } 073 074 return filter(src, dst); 075 } 076 } 077