1、算法

R = |g – b + g + r| * r / 256

G = |b – g + b + r| * r / 256;

B = |b – g + b + r| * g / 256;

然后灰化。

2、代码实现

public Bitmap render(Bitmap bitmap)  {    if(bitmap == null)return null;    int width = bitmap.getWidth();    int height = bitmap.getHeight();    int[] pixels = new int[width * height];    bitmap.getPixels(pixels ,0 , width , 0 , 0 , width , height);    for(int i=0 ; i
     
      >16;        int g = (pixel & 0x0000ff00)>>8;        int b = (pixel & 0x000000ff);        r = algorithm(g , b , r , r);        g = algorithm(b , g , r , r);        b = algorithm(b , g , r , g);        int gray = (r*3+g*6+b)/10;        pixels[i*width +j] = (pixel & 0xff000000) + (gray<<16)+ (gray<<8) +gray;      }    }    return Bitmap.createBitmap(pixels ,width , height , Config.ARGB_8888);  } public int algorithm(int doubleValue , int negative , int positive , int multi){  int  value = 2*doubleValue - negative +positive;  if(value<0)  {    value = -value;  }  value = value * multi /256;  if(value>255)  {    value = 255;  }  return value;}