图像处理之光束效果
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：
/* ** 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..."; } }
移动模糊 - 参见博客文章 《图像处理之移动模糊》
