图片处理边缘高亮

1、算法

r = Math.sqrt((r- rightr)^2 + (r-bottomr)^2)*2

g = Math.sqrt((g- rightg)^2 + (g-bottomg)^2)*2

b = Math.sqrt((b- rightb)^2 + (b-bottomb)^2)*2

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);

    int rectTop = 0;
    int rectBottom = height-1;
    int rectLeft = 0;
    int rectRight = width-1;

    for(int i=rectTop ; i<rectBottom ; i++)
    {
      for(int j=rectLeft ; j<rectRight ; j++)
      {
        int pixel = pixels[i*width +j];
        int leftPixel = pixels[i*width +j+1];
        int bottomPixel = pixels[i*width +j +width];
        int r = (pixel & 0x00ff0000)>>16;
        int g = (pixel & 0x0000ff00)>>8;
        int b = (pixel & 0x000000ff);

        int leftR = (leftPixel & 0x00ff0000)>>16;
        int leftG = (leftPixel & 0x0000ff00)>>8;
        int leftB = (leftPixel & 0x000000ff);

        int bottomR = (bottomPixel & 0x00ff0000)>>16;
        int bottomG = (bottomPixel & 0x0000ff00)>>8;
        int bottomB = (bottomPixel & 0x000000ff);
        r = algorithm(r , leftR , bottomR);
        g = algorithm(g , leftG , bottomG);
        b = algorithm(b , leftB , bottomB);
        pixels[i*width +j] = (pixel & 0xff000000) + (r<<16)+ (g<<8) +b;
      }
    }

    return Bitmap.createBitmap(pixels ,width , height , Config.ARGB_8888);
  }
                                    
public int algorithm(int value , int leftValue , int bottomValue)
{

  int pixel = (int)(Math.pow(value-bottomValue , 2) + Math.pow(value-leftValue , 2) ) ;
  pixel = (int)(Math.sqrt(pixel) * 2);
  if(pixel<0)
  {
    pixel = 0;
  }

  if(pixel>255)
  {
    pixel = 255;
  }
  return pixel;
}