图像处理之水纹效果

package com.gloomyfish.filter.study;
 
import java.awt.image.BufferedImage;
 
public class WaterFilter extends AbstractBufferedImageOp {
  
  private double wave;
  private double period;
  
  public WaterFilter() {
    wave = 25.0;
    period = 128;
  }
  
  public void setPeriod(double period) {
    this.period = period;
  }
  
  public void setWave(double nWave) {
    this.wave = nWave;
  }
 
  @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];
        Point[][] ssPixels = new Point[height][width];
        getRGB( src, 0, 0, width, height, inPixels );
        int index = 0, index2 = 0;
        int xoffset = 0, yoffset = 0;
        for(int row=0; row<height; row++) {
          for(int col=0; col<width; col++) {
                xoffset = (int)((double)wave * Math.sin(2.0 * Math.PI * (float)row / period));
                yoffset = (int)((double)wave * Math.cos(2.0 * Math.PI * (float)col / period));
                xoffset = xoffset + col;
                yoffset = yoffset + row;
                if(xoffset < 0 || xoffset >=width) {
                  xoffset = 0;
                }
                if(yoffset < 0 || yoffset >=height) {
                  yoffset = 0;
                }
                
                // save the 2D coordinate newX, and newY
                ssPixels[row][col] = new Point(xoffset, yoffset); 
          }
        }
        
        // coordinate 2D result and fill the pixels data.
        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;
            index2 = ssPixels[row][col].getRow() * width + ssPixels[row][col].getCol();
            ta = (inPixels[index2] >> 24) & 0xff;
                tr = (inPixels[index2] >> 16) & 0xff;
                tg = (inPixels[index2] >> 8) & 0xff;
                tb = inPixels[index2] & 0xff;
                outPixels[index] = (ta << 24) | (tr << 16) | (tg << 8) | tb;
          }
        }
        setRGB( dest, 0, 0, width, height, outPixels );
        return dest;
  }
  
  class Point {
    private int x;
    private int y;
    
    public Point(int x, int y) {
      this.x = x;
      this.y = y;
    }
    
    public int getRow() {
      return this.y;
    }
    
    public int getCol() {
      return this.x;
    }
    
  }
 
}