IOS – OpenGL ES 图像加亮边缘 GPUImage3x3ConvolutionFilter

IOS – OpenGL ES 图像加亮边缘 GPUImage3x3ConvolutionFilter

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.

GPUImage3x3ConvolutionFilter 属于 GPUImage 图像视觉效果相关,用来处理图像加亮边缘。shader 源码如下:

/******************************************************************************************/
//@Author:猿说编程
//@Blog(个人博客地址): www.codersrc.com
//@File:IOS – OpenGL ES 图像加亮边缘 GPUImage3x3ConvolutionFilter
//@Time:2022/06/08 06:30
//@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 kGPUImage3x3ConvolutionFragmentShaderString = SHADER_STRING
(
 precision highp float;

 uniform sampler2D inputImageTexture;
 
 uniform mediump mat3 convolutionMatrix;
 
 varying vec2 textureCoordinate;
 varying vec2 leftTextureCoordinate;
 varying vec2 rightTextureCoordinate;
 
 varying vec2 topTextureCoordinate;
 varying vec2 topLeftTextureCoordinate;
 varying vec2 topRightTextureCoordinate;
 
 varying vec2 bottomTextureCoordinate;
 varying vec2 bottomLeftTextureCoordinate;
 varying vec2 bottomRightTextureCoordinate;
 
 void main()
 {
     mediump vec3 bottomColor = texture2D(inputImageTexture, bottomTextureCoordinate).rgb;
     mediump vec3 bottomLeftColor = texture2D(inputImageTexture, bottomLeftTextureCoordinate).rgb;
     mediump vec3 bottomRightColor = texture2D(inputImageTexture, bottomRightTextureCoordinate).rgb;
     mediump vec4 centerColor = texture2D(inputImageTexture, textureCoordinate);
     mediump vec3 leftColor = texture2D(inputImageTexture, leftTextureCoordinate).rgb;
     mediump vec3 rightColor = texture2D(inputImageTexture, rightTextureCoordinate).rgb;
     mediump vec3 topColor = texture2D(inputImageTexture, topTextureCoordinate).rgb;
     mediump vec3 topRightColor = texture2D(inputImageTexture, topRightTextureCoordinate).rgb;
     mediump vec3 topLeftColor = texture2D(inputImageTexture, topLeftTextureCoordinate).rgb;

     mediump vec3 resultColor = topLeftColor * convolutionMatrix[0][0] + topColor * convolutionMatrix[0][1] + topRightColor * convolutionMatrix[0][2];
     resultColor += leftColor * convolutionMatrix[1][0] + centerColor.rgb * convolutionMatrix[1][1] + rightColor * convolutionMatrix[1][2];
     resultColor += bottomLeftColor * convolutionMatrix[2][0] + bottomColor * convolutionMatrix[2][1] + bottomRightColor * convolutionMatrix[2][2];

     gl_FragColor = vec4(resultColor, centerColor.a);
 }
);                                                                         
#else
NSString *const kGPUImage3x3ConvolutionFragmentShaderString = SHADER_STRING
(
 uniform sampler2D inputImageTexture;
 
 uniform mat3 convolutionMatrix;
 
 varying vec2 textureCoordinate;
 varying vec2 leftTextureCoordinate;
 varying vec2 rightTextureCoordinate;
 
 varying vec2 topTextureCoordinate;
 varying vec2 topLeftTextureCoordinate;
 varying vec2 topRightTextureCoordinate;
 
 varying vec2 bottomTextureCoordinate;
 varying vec2 bottomLeftTextureCoordinate;
 varying vec2 bottomRightTextureCoordinate;
 
 void main()
 {
     vec3 bottomColor = texture2D(inputImageTexture, bottomTextureCoordinate).rgb;
     vec3 bottomLeftColor = texture2D(inputImageTexture, bottomLeftTextureCoordinate).rgb;
     vec3 bottomRightColor = texture2D(inputImageTexture, bottomRightTextureCoordinate).rgb;
     vec4 centerColor = texture2D(inputImageTexture, textureCoordinate);
     vec3 leftColor = texture2D(inputImageTexture, leftTextureCoordinate).rgb;
     vec3 rightColor = texture2D(inputImageTexture, rightTextureCoordinate).rgb;
     vec3 topColor = texture2D(inputImageTexture, topTextureCoordinate).rgb;
     vec3 topRightColor = texture2D(inputImageTexture, topRightTextureCoordinate).rgb;
     vec3 topLeftColor = texture2D(inputImageTexture, topLeftTextureCoordinate).rgb;
     
     vec3 resultColor = topLeftColor * convolutionMatrix[0][0] + topColor * convolutionMatrix[0][1] + topRightColor * convolutionMatrix[0][2];
     resultColor += leftColor * convolutionMatrix[1][0] + centerColor.rgb * convolutionMatrix[1][1] + rightColor * convolutionMatrix[1][2];
     resultColor += bottomLeftColor * convolutionMatrix[2][0] + bottomColor * convolutionMatrix[2][1] + bottomRightColor * convolutionMatrix[2][2];
     
     gl_FragColor = vec4(resultColor, centerColor.a);
 }
);
#endif

二.效果演示

使用GPUImage3x3ConvolutionFilter 完成图像加亮边缘,原图如下:

使用GPUImage3x3ConvolutionFilter 完成图像加亮边缘,效果如下:


三.源码下载

OpenGL ES Demo 下载地址 : IOS – OpenGL ES 图像加亮边缘 GPUImage3x3ConvolutionFilter


四.猜你喜欢

  1. IOS – OPenGL ES 设置图像亮度 GPUImageBrightnessFilter
  2. IOS – OPenGL ES 调节图像曝光度 GPUImageExposureFilter
  3. IOS – OpenGL ES 调节图像对比度 GPUImageContrastFilter
  4. IOS – OPenGL ES 调节图像饱和度 GPUImageSaturationFilter
  5. IOS – OPenGL ES 调节图像伽马线 GPUImageGammaFilter
  6. IOS – OpenGL ES 调节图像反色 GPUImageColorInvertFilter
  7. IOS – OpenGL ES 调节图像褐色 GPUImageSepiaFilter
  8. IOS – OpenGL ES 调节图像灰色 GPUImageGrayscaleFilter
  9. IOS – OpenGL ES 调节图像RGB通道 GPUImageRGBFilter
  10. IOS – OpenGL ES 调节图像不透明度 GPUImageOpacityFilter
  11. IOS – OpenGL ES 调节图像阴影 GPUImageHighlightShadowFilter
  12. IOS – OpenGL ES 调节图像色彩替换 GPUImageFalseColorFilter
  13. GPUImage – 色彩直方图 GPUImageHistogramFilter
  14. GPUImage – 色彩直方图 GPUImageHistogramGenerator
  15. GPUImage – 像素平均色值 GPUImageAverageColor
  16. GPUImage – 亮度平均 GPUImageLuminosity
  17. IOS – OpenGL ES 调节图像色度 GPUImageHueFilter
  18. IOS – OpenGL ES 指定颜色抠图 GPUImageChromaKeyFilter
  19. IOS – OpenGL ES 调节图像白平衡/色温 GPUImageWhiteBalanceFilter
  20. IOS – OpenGL ES 设置图像 lookup 滤镜 GPUImageLookupFilter
  21. IOS – OpenGL ES 设置图像滤镜 GPUImageAmatorkaFilter
  22. IOS – OpenGL ES 设置图像滤镜 GPUImageSoftEleganceFilter
  23. IOS – OpenGL ES 设置图像锐化 GPUImageSharpenFilter
  24. IOS – OpenGL ES 绘制十字 GPUImageCrosshairGenerator
  25. IOS – OpenGL ES 绘制线条 GPUImageLineGenerator
  26. IOS – OpenGL ES 设置图像黑白燥点 GPUImageLocalBinaryPatternFilter
  27. IOS – OpenGL ES 设置图像卡通效果(黑色粗线描边) GPUImageToonFilter
  28. IOS – OpenGL ES 桑原滤波/水粉画模糊效果 GPUImageKuwaharaFilter
  29. IOS – OpenGL ES 黑白马赛克效果 GPUImageMosaicFilter
  30. IOS – OpenGL ES 像素化马赛克效果 GPUImagePixellateFilter
  31. IOS – OpenGL ES 同心圆像素化马赛克效果 GPUImagePolarPixel
  32. IOS – OpenGL ES 黑白网状效果 GPUImageCrosshatchFilter
  33. IOS – OpenGL ES 色彩丢失/模糊效果 GPUImageColorPackingFilter
  34. IOS – OpenGL ES 图像晕影 GPUImageVignetteFilter
  35. IOS – OpenGL ES 图像漩涡 GPUImageSwirlFilter
  36. IOS – OpenGL ES 图像鱼眼扩散效果 GPUImageBulgeDistortionFilter
  37. IOS – OpenGL ES 图像鱼眼移动效果 GPUImageBulgeDistortionFilter
  38. IOS – OpenGL ES 图像凹面镜移动效果 GPUImagePinchDistortionFilter
  39. IOS – OpenGL ES 图像凹面镜放大效果 GPUImagePinchDistortionFilter
  40. IOS – OpenGL ES 图像哈哈镜效果 GPUImageStretchDistortionFilter
  41. IOS – OpenGL ES 图像水晶球效果 GPUImageGlassSphereFilter
  42. IOS – OpenGL ES 图像球形折射 GPUImageSphereRefractionFilter
  43. IOS – OpenGL ES 图像色调分离噪点效果 GPUImagePosterizeFilter
  44. IOS – OpenGL ES 图像CGA色彩滤镜 GPUImageCGAColorspaceFilter
  45. IOS – OpenGL ES 图像柏林噪点/花边噪点 GPUImagePerlinNoiseFilter
  46. IOS – OpenGL ES 图像加亮边缘 GPUImage3x3ConvolutionFilter

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