图像处理------边缘褪化效果

很多图像处理软件都提供边缘褪化效果滤镜，其实原理非常的简单，网上搜索了一把，实现了基于Java的图像边缘褪化效果。边缘褪化效果取决于以下三个参数：1. 设定的图像边缘宽度2. 褪化比率– 其实质是图像融合的百分比数3. 选择的边框颜色 主要原理是计算图像中的像素点到中心点的距离，对边缘像素根据褪化比率与选择的边框颜色融合从而产生褪化效果。程序效果如下：原图：


处理以后图像：


滤镜的完全源代码如下：[java] view plaincopypackage com.process.blur.study;

import java.awt.Color;
import java.awt.image.BufferedImage;

/**
* @author gloomy fish
* Vignette - a photograph whose edges shade off gradually
*
*/
public class VignetteFilter extends AbstractBufferedImageOp {

private int vignetteWidth;
private int fade;
private Color vignetteColor;

public VignetteFilter() {
vignetteWidth = 50;
fade = 35;
vignetteColor = Color.BLACK;
}

@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++) {

int dX = Math.min(col, width - col);
int dY = Math.min(row, height - row);
index = row * width + col;
ta = (inPixels[index] >> 24) & 0xff;
tr = (inPixels[index] >> 16) & 0xff;
tg = (inPixels[index] >> 8) & 0xff;
tb = inPixels[index] & 0xff;
if ((dY <= vignetteWidth) & (dX <= vignetteWidth))
{
double k = 1 - (double)(Math.min(dY, dX) - vignetteWidth + fade) / (double)fade;
outPixels[index] = superpositionColor(ta, tr, tg, tb, k);
continue;
}

if ((dX < (vignetteWidth - fade)) | (dY < (vignetteWidth - fade)))
{
outPixels[index] = (ta << 24) | (vignetteColor.getRed() << 16) | (vignetteColor.getGreen() << 8) | vignetteColor.getBlue();
}
else
{
if ((dX < vignetteWidth)&(dY>vignetteWidth))
{
double k = 1 - (double)(dX - vignetteWidth + fade) / (double)fade;
outPixels[index] = superpositionColor(ta, tr, tg, tb, k);
}
else
{
if ((dY < vignetteWidth)&(dX > vignetteWidth))
{
double k = 1 - (double)(dY - vignetteWidth + fade) / (double)fade;
outPixels[index] = superpositionColor(ta, tr, tg, tb, k);
}
else
{
outPixels[index] = (ta << 24) | (tr << 16) | (tg << 8) | tb;
}
}
}
}
}

setRGB( dest, 0, 0, width, height, outPixels );
return dest;
}

public int superpositionColor(int ta, int red, int green, int blue, double k) {
red = (int)(vignetteColor.getRed() * k + red *(1.0-k));
green = (int)(vignetteColor.getGreen() * k + green *(1.0-k));
blue = (int)(vignetteColor.getBlue() * k + blue *(1.0-k));
int color = (ta << 24) | (clamp(red) << 16) | (clamp(green) << 8) | clamp(blue);
return color;
}

public int clamp(int value) {
return value > 255 ? 255 :((value < 0) ? 0 : value);
}

public int getVignetteWidth() {
return vignetteWidth;
}

public void setVignetteWidth(int vignetteWidth) {
this.vignetteWidth = vignetteWidth;
}

public int getFade() {
return fade;
}

public void setFade(int fade) {
this.fade = fade;
}

public Color getVignetteColor() {
return vignetteColor;
}

public void setVignetteColor(Color vignetteColor) {
this.vignetteColor = vignetteColor;
}

}