介绍几种常见的将两张图像混合在一起形成一张新的图像的算法，
首先看一下下面算法演示中要使用的两张图像：
为了得到更好的混合效果，我选择了两张一样大小的图片。
方法一：
通过简单对于像素点的像素相乘得到输出像素值，代码演示如下：
private int modeOne(int v1, int v2) { return (v1 * v2) / 255; }
方法一的效果如下：
方法二：
通过计算两个像素之和再减去方法一的输出值，代码如下：
private int modeTwo(int v1, int v2) { return v1 + v2 - v1 * v2 / 255; }
方法二的效果如下：
方法三：
通过像素值128这个特殊的中值来求取输出值，代码如下：
private int modeThree(int v1, int v2) { return (v2 < 128) ? (2 * v1 * v2 / 255):(255 - 2 * (255 - v1) * (255 - v2) / 255); }
方法三的效果如下：
方法四：
与方法三不同，中值127.5被用在计算等式中，代码如下：
private int modeFour(double v1, double v2) { if ( v1 > 127.5 ){ return (int)(v2 + (255.0 - v2) * ((v1 - 127.5) / 127.5) * (0.5 - Math.abs(v2-127.5)/255.0)); }else{ return (int)(v2 - v2 * ((127.5 - v1) / 127.5) * (0.5 - Math.abs(v2-127.5)/255.0)); } }
方法四的效果如下：
方法五：
中值计算考虑，是方法一的升级版本，使得混合更加精细,代码如下：
private int modeFive(double v1, double v2) { if ( v1 > 127.5 ){ return (int)(v2 + (255.0 - v2) * ((v1 - 127.5) / 127.5)); }else{ return (int)(v2 * v1 / 127.5); } }
方法五的效果如下：
滤镜源代码如下：
package com.gloomyfish.filter.study; import java.awt.image.BufferedImage; /*** * i get these blend method from html5 demo then i decide to * translate these java script methods into java * 偶尔我也会写中文注释, 常见的图像混合方法 * @author fish * @date 2012-11-28 */ public class ImageBlendFilter extends AbstractBufferedImageOp { /** Define the blend mode */ public final static int MULTIPLY_PIXEL = 1; public final static int SCREEN_PIXEL = 2; public final static int OVERLAY_PIXEL = 3; public final static int SOFTLIGHT_PIXEL = 4; public final static int HARDLIGHT_PIXEL = 5; private int mode; private BufferedImage secondImage; public ImageBlendFilter() { mode = 1; } public void setBlendMode(int mode) { this.mode = mode; } public void setSecondImage(BufferedImage image) { this.secondImage = image; } @Override public BufferedImage filter(BufferedImage src, BufferedImage dest) { checkImages(src); int width = src.getWidth(); int height = src.getHeight(); if ( dest == null ) dest = createCompatibleDestImage( src, null ); int[] input1 = new int[width*height]; int[] input2 = new int[secondImage.getWidth() * secondImage.getHeight()]; int[] outPixels = new int[width*height]; getRGB( src, 0, 0, width, height, input1); getRGB( secondImage, 0, 0, secondImage.getWidth(), secondImage.getHeight(), input2); int index = 0; int ta1 = 0, tr1 = 0, tg1 = 0, tb1 = 0; for(int row=0; row<height; row++) { for(int col=0; col<width; col++) { index = row * width + col; ta1 = (input1[index] >> 24) & 0xff; tr1 = (input1[index] >> 16) & 0xff; tg1 = (input1[index] >> 8) & 0xff; tb1 = input1[index] & 0xff; int[] rgb = getBlendData(tr1, tg1, tb1, input2, row, col); outPixels[index] = (ta1 << 24) | (rgb[0] << 16) | (rgb[1] << 8) | rgb[2]; } } setRGB( dest, 0, 0, width, height, outPixels ); return dest; } private int[] getBlendData(int tr1, int tg1, int tb1, int[] input,int row, int col) { int width = secondImage.getWidth(); int height = secondImage.getHeight(); if(col >= width || row >= height) { return new int[]{tr1, tg1, tb1}; } int index = row * width + col; // int ta = (input[index] >> 24) & 0xff; int tr = (input[index] >> 16) & 0xff; int tg = (input[index] >> 8) & 0xff; int tb = input[index] & 0xff; int[] rgb = new int[3]; if(mode == 1) { rgb[0] = modeOne(tr1, tr); rgb[1] = modeOne(tg1, tg); rgb[2] = modeOne(tb1, tb); } else if(mode == 2) { rgb[0] = modeTwo(tr1, tr); rgb[1] = modeTwo(tg1, tg); rgb[2] = modeTwo(tb1, tb); } else if(mode == 3) { rgb[0] = modeThree(tr1, tr); rgb[1] = modeThree(tg1, tg); rgb[2] = modeThree(tb1, tb); } else if(mode == 4) { rgb[0] = modeFour(tr1, tr); rgb[1] = modeFour(tg1, tg); rgb[2] = modeFour(tb1, tb); } else if(mode == 5) { rgb[0] = modeFive(tr1, tr); rgb[1] = modeFive(tg1, tg); rgb[2] = modeFive(tb1, tb); } return rgb; } private int modeOne(int v1, int v2) { return (v1 * v2) / 255; } private int modeTwo(int v1, int v2) { return v1 + v2 - v1 * v2 / 255; } private int modeThree(int v1, int v2) { return (v2 < 128) ? (2 * v1 * v2 / 255):(255 - 2 * (255 - v1) * (255 - v2) / 255); } private int modeFour(double v1, double v2) { if ( v1 > 127.5 ){ return (int)(v2 + (255.0 - v2) * ((v1 - 127.5) / 127.5) * (0.5 - Math.abs(v2-127.5)/255.0)); }else{ return (int)(v2 - v2 * ((127.5 - v1) / 127.5) * (0.5 - Math.abs(v2-127.5)/255.0)); } } private int modeFive(double v1, double v2) { if ( v1 > 127.5 ){ return (int)(v2 + (255.0 - v2) * ((v1 - 127.5) / 127.5)); }else{ return (int)(v2 * v1 / 127.5); } } private void checkImages(BufferedImage src) { int width = src.getWidth(); int height = src.getHeight(); if(secondImage == null || secondImage.getWidth() > width || secondImage.getHeight() > height) { throw new IllegalArgumentException("the width, height of the input image must be great than blend image"); } } }
如果觉得效果很有趣，请顶一下，谢谢！
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