IOS – OpenGL ES 桑原滤波/水粉画模糊效果 GPUImageKuwaharaFilter

一.简介
二.效果演示
三.源码下载
四.猜你喜欢

零基础 OpenGL (ES) 学习路线推荐 : OpenGL (ES) 学习目录 >> OpenGL ES 基础

零基础 OpenGL (ES) 学习路线推荐 : OpenGL (ES) 学习目录 >> OpenGL ES 转场

零基础 OpenGL (ES) 学习路线推荐 : OpenGL (ES) 学习目录 >> OpenGL ES 特效

零基础 OpenGL (ES) 学习路线推荐 : OpenGL (ES) 学习目录 >> OpenGL ES 函数

零基础 OpenGL (ES) 学习路线推荐 : OpenGL (ES) 学习目录 >> OpenGL ES GPUImage 使用

零基础 OpenGL (ES) 学习路线推荐 : OpenGL (ES) 学习目录 >> OpenGL ES GLSL 编程

一.简介

GPUImage 共 125 个滤镜, 分为四类

1、Color adjustments : 31 filters , 颜色处理相关
2、Image processing : 40 filters , 图像处理相关.
3、Blending modes : 29 filters , 混合模式相关.
4、Visual effects : 25 filters , 视觉效果相关.

**GPUImageKuwaharaFilter GPUImage 图像桑原滤波/水粉画模糊效果，**shader 源码如下：

/******************************************************************************************/
//@Author:猿说编程
//@Blog(个人博客地址): www.codersrc.com
//@File:IOS – OpenGL ES 桑原滤波/水粉画模糊效果 GPUImageKuwaharaFilter
//@Time:2022/05/15 10:30
//@Motto:不积跬步无以至千里，不积小流无以成江海，程序人生的精彩需要坚持不懈地积累！
/******************************************************************************************/
#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE
NSString *const kGPUImageKuwaharaFragmentShaderString = SHADER_STRING
(varying highp vec2 textureCoordinate;uniform sampler2D inputImageTexture;uniform int radius;precision highp float;const vec2 src_size = vec2 (1.0 / 768.0, 1.0 / 1024.0);void main (void){vec2 uv = textureCoordinate;float n = float((radius + 1) * (radius + 1));int i; int j;vec3 m0 = vec3(0.0); vec3 m1 = vec3(0.0); vec3 m2 = vec3(0.0); vec3 m3 = vec3(0.0);vec3 s0 = vec3(0.0); vec3 s1 = vec3(0.0); vec3 s2 = vec3(0.0); vec3 s3 = vec3(0.0);vec3 c;for (j = -radius; j <= 0; ++j)  {for (i = -radius; i <= 0; ++i)  {c = texture2D(inputImageTexture, uv + vec2(i,j) * src_size).rgb;m0 += c;s0 += c * c;}}for (j = -radius; j <= 0; ++j)  {for (i = 0; i <= radius; ++i)  {c = texture2D(inputImageTexture, uv + vec2(i,j) * src_size).rgb;m1 += c;s1 += c * c;}}for (j = 0; j <= radius; ++j)  {for (i = 0; i <= radius; ++i)  {c = texture2D(inputImageTexture, uv + vec2(i,j) * src_size).rgb;m2 += c;s2 += c * c;}}for (j = 0; j <= radius; ++j)  {for (i = -radius; i <= 0; ++i)  {c = texture2D(inputImageTexture, uv + vec2(i,j) * src_size).rgb;m3 += c;s3 += c * c;}}float min_sigma2 = 1e+2;m0 /= n;s0 = abs(s0 / n - m0 * m0);float sigma2 = s0.r + s0.g + s0.b;if (sigma2 < min_sigma2) {min_sigma2 = sigma2;gl_FragColor = vec4(m0, 1.0);}m1 /= n;s1 = abs(s1 / n - m1 * m1);sigma2 = s1.r + s1.g + s1.b;if (sigma2 < min_sigma2) {min_sigma2 = sigma2;gl_FragColor = vec4(m1, 1.0);}m2 /= n;s2 = abs(s2 / n - m2 * m2);sigma2 = s2.r + s2.g + s2.b;if (sigma2 < min_sigma2) {min_sigma2 = sigma2;gl_FragColor = vec4(m2, 1.0);}m3 /= n;s3 = abs(s3 / n - m3 * m3);sigma2 = s3.r + s3.g + s3.b;if (sigma2 < min_sigma2) {min_sigma2 = sigma2;gl_FragColor = vec4(m3, 1.0);}}
);
#else
NSString *const kGPUImageKuwaharaFragmentShaderString = SHADER_STRING
(varying vec2 textureCoordinate;uniform sampler2D inputImageTexture;uniform int radius;const vec2 src_size = vec2 (1.0 / 768.0, 1.0 / 1024.0);void main (void){vec2 uv = textureCoordinate;float n = float((radius + 1) * (radius + 1));int i; int j;vec3 m0 = vec3(0.0); vec3 m1 = vec3(0.0); vec3 m2 = vec3(0.0); vec3 m3 = vec3(0.0);vec3 s0 = vec3(0.0); vec3 s1 = vec3(0.0); vec3 s2 = vec3(0.0); vec3 s3 = vec3(0.0);vec3 c;for (j = -radius; j <= 0; ++j)  {for (i = -radius; i <= 0; ++i)  {c = texture2D(inputImageTexture, uv + vec2(i,j) * src_size).rgb;m0 += c;s0 += c * c;}}for (j = -radius; j <= 0; ++j)  {for (i = 0; i <= radius; ++i)  {c = texture2D(inputImageTexture, uv + vec2(i,j) * src_size).rgb;m1 += c;s1 += c * c;}}for (j = 0; j <= radius; ++j)  {for (i = 0; i <= radius; ++i)  {c = texture2D(inputImageTexture, uv + vec2(i,j) * src_size).rgb;m2 += c;s2 += c * c;}}for (j = 0; j <= radius; ++j)  {for (i = -radius; i <= 0; ++i)  {c = texture2D(inputImageTexture, uv + vec2(i,j) * src_size).rgb;m3 += c;s3 += c * c;}}float min_sigma2 = 1e+2;m0 /= n;s0 = abs(s0 / n - m0 * m0);float sigma2 = s0.r + s0.g + s0.b;if (sigma2 < min_sigma2) {min_sigma2 = sigma2;gl_FragColor = vec4(m0, 1.0);}m1 /= n;s1 = abs(s1 / n - m1 * m1);sigma2 = s1.r + s1.g + s1.b;if (sigma2 < min_sigma2) {min_sigma2 = sigma2;gl_FragColor = vec4(m1, 1.0);}m2 /= n;s2 = abs(s2 / n - m2 * m2);sigma2 = s2.r + s2.g + s2.b;if (sigma2 < min_sigma2) {min_sigma2 = sigma2;gl_FragColor = vec4(m2, 1.0);}m3 /= n;s3 = abs(s3 / n - m3 * m3);sigma2 = s3.r + s3.g + s3.b;if (sigma2 < min_sigma2) {min_sigma2 = sigma2;gl_FragColor = vec4(m3, 1.0);}}
);
#endif