PS中有一种滤镜可以让图像看上去好像历经岁月，微微泛黄 英文中这种图像特效被称为Sepia Tone Effect 直译过来的意思

int fr= (int)(((double)tr * 0.393) + ((double)tg * 0.769) + ((double)tb * 0.189));    int fg = (int)(((double)tr * 0.349) + ((double)tg * 0.686) + ((double)tb * 0.168));     int fb= (int)(((double)tr * 0.272) + ((double)tg * 0.534) + ((double)tb * 0.131));      

2. 对图像计算出来的新的RGB值根据随机权重与旧值混合。
计算随机权重的代码如下：

  private double noise() {        return Math.random()*0.5 + 0.5;    }      

混合颜色的代码如下：

  private double colorBlend(double scale, double dest, double src) {        return (scale * dest + (1.0 - scale) * src);    }          

滤镜完全源代码：

  package com.gloomyfish.filter.study;        import java.awt.image.BufferedImage;        public class SepiaToneFilter extends AbstractBufferedImageOp {            @Override        public BufferedImage filter(BufferedImage src, BufferedImage dest) {            int width = src.getWidth();            int height = src.getHeight();                if ( dest == null )                dest = createCompatibleDestImage( src, null );                int[] inPixels = new int[width*height];            int[] outPixels = new int[width*height];            getRGB( src, 0, 0, width, height, inPixels );            int index = 0;            for(int row=0; row<height; row++) {                int ta = 0, tr = 0, tg = 0, tb = 0;                for(int col=0; col<width; col++) {                    index = row * width + col;                    ta = (inPixels[index] >> 24) & 0xff;                    tr = (inPixels[index] >> 16) & 0xff;                    tg = (inPixels[index] >> 8) & 0xff;                    tb = inPixels[index] & 0xff;        //int fr= (int)(((double)tr * 0.393) + ((double)tg * 0.769) + ((double)tb * 0.189));    //int fg = (int)(((double)tr * 0.349) + ((double)tg * 0.686) + ((double)tb * 0.168));     //int fb= (int)(((double)tr * 0.272) + ((double)tg * 0.534) + ((double)tb * 0.131));                                        int fr = (int)colorBlend(noise(), (tr * 0.393) + (tg * 0.769) + (tb * 0.189), tr);                    int fg = (int)colorBlend(noise(), (tr * 0.349) + (tg * 0.686) + (tb * 0.168), tg);                    int fb = (int)colorBlend(noise(), (tr * 0.272) + (tg * 0.534) + (tb * 0.131), tb);                                        outPixels[index] = (ta << 24) | (clamp(fr) << 16) | (clamp(fg) << 8) | clamp(fb);                                    }            }            setRGB( dest, 0, 0, width, height, outPixels );            return dest;        }                private double noise() {            return Math.random()*0.5 + 0.5;        }                private double colorBlend(double scale, double dest, double src) {            return (scale * dest + (1.0 - scale) * src);        }                public static int clamp(int c)        {            return c > 255 ? 255 :( (c < 0) ? 0: c);        }                public String toString()        {            return "Sepia Tone Effect - Effect from Photoshop App";        }        }