原理：
光束滤镜，对一幅图像完成光束效果，好似有一束光从图像本身激发出来，按照一定的角度
散发开来，光束滤镜是一种图像叠加效果，首先要借助于之前的完成的移动模糊滤镜，将一
幅图像按照一定的阈值二值化以后，加以移动模糊滤镜，将移动模糊之后的图像和原图像叠
加就产生了光束滤镜效果。
对光束滤镜而言，其最终效果除了移动模糊的三个参数以外，还取决于以下两个参数：
a. 图像RGB阈值的选取，建议可以直方图以后选取，程序以threshold表示
b. 光强度大小的值的选取，程序中以strength表示
程序运行效果如下：
关键代码解析：
计算RGB阈值代码如下– 输入的阈值范围为[0,1]
intthreshold3 = (int)(threshold*3*255);
求取二值像素的代码如下：
int l = r + g + b;
if (l < threshold3)
[x] =0xff000000;
else {
l /= 3;
pixels[x] = a | (l << 16) | (l << 8) | l;
}
像素叠加乘以强度系数的代码如下（其中r,g,b分别代表RGB的三个颜色分量值）：
r = PixelUtils.clamp((int)(r * strength) + r2);
g = PixelUtils.clamp((int)(g * strength) + g2);
b = PixelUtils.clamp((int)(b * strength) + b2);
光束滤镜的完全源代码如下：
- <span style="font-weight: normal;">/*
- ** Copyright 2012 @gloomyfish. All rights reserved.
- */
- package com.process.blur.study;
- import java.awt.image.BufferedImage;
- public class LaserFilter extends MotionFilter {
- private float threshold = 0.5f;
- private float strength = 0.8f;
- public LaserFilter() {
- }
- public void setThreshold( float threshold ) {
- this.threshold = threshold;
- }
- public float getThreshold() {
- return threshold;
- }
- public void setStrength( float strength ) {
- this.strength = strength;
- }
- public float getStrength() {
- return strength;
- }
- public BufferedImage filter( BufferedImage src, BufferedImage dst ) {
- int width = src.getWidth();
- int height = src.getHeight();
- int[] pixels = new int[width];
- int[] srcPixels = new int[width];
- BufferedImage laserImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
- int threshold3 = (int)(threshold*3*255);
- for ( int y = 0; y < height; y++ ) {
- getRGB( src, 0, y, width, 1, pixels );
- for ( int x = 0; x < width; x++ ) {
- int rgb = pixels[x];
- int a = rgb & 0xff000000;
- int r = (rgb >> 16) & 0xff;
- int g = (rgb >> 8) & 0xff;
- int b = rgb & 0xff;
- int l = r + g + b;
- if (l < threshold3)
- pixels[x] = 0xff000000;
- else {
- l /= 3;
- pixels[x] = a | (l << 16) | (l << 8) | l;
- }
- }
- setRGB( laserImg, 0, y, width, 1, pixels );
- }
- laserImg = super.filter(laserImg, null );
- for ( int y = 0; y < height; y++ ) {
- getRGB( laserImg, 0, y, width, 1, pixels );
- getRGB( src, 0, y, width, 1, srcPixels );
- for ( int x = 0; x < width; x++ ) {
- int rgb = pixels[x];
- int a = rgb & 0xff000000;
- int r = (rgb >> 16) & 0xff;
- int g = (rgb >> 8) & 0xff;
- int b = rgb & 0xff;
- int rgb2 = srcPixels[x];
- // int a2 = rgb2 & 0xff000000;
- int r2 = (rgb2 >> 16) & 0xff;
- int g2 = (rgb2 >> 8) & 0xff;
- int b2 = rgb2 & 0xff;
- if ( r > 0 ) {
- r = clamp((int)(r * strength) + r2);
- g = clamp((int)(g * strength) + g2);
- b = clamp((int)(b * strength) + b2);
- } else {
- r = r2;
- g = g2;
- b = b2;
- }
- rgb = a | (r << 16) | (g << 8) | b;
- pixels[x] = rgb;
- }
- setRGB( laserImg, 0, y, width, 1, pixels );
- }
- return laserImg;
- }
- public String toString() {
- return "Light/Laser...";
- }
- }
- </span>
