IOS – OpenGL ES 调节图像单色 GPUImageMonochromeFilter

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.

GPUImageMonochromeFilter 属于 GPUImage 颜色处理相关，用来处理图片单色，shader 源码如下：

/********************************************************************************************/
//@Author:猿说编程
//@Blog(个人博客地址): www.codersrc.com
//@File:IOS – OpenGL ES 调节图像单色 GPUImageMonochromeFilter
//@Time:2022/03/18 07:30
//@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 kGPUMonochromeFragmentShaderString = SHADER_STRING
(
 precision lowp float;
 
 varying highp vec2 textureCoordinate;
 
 uniform sampler2D inputImageTexture;
 uniform float intensity;
 uniform vec3 filterColor;
 
 const mediump vec3 luminanceWeighting = vec3(0.2125, 0.7154, 0.0721);
 
 void main()
 {
  //desat, then apply overlay blend
  lowp vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);
  float luminance = dot(textureColor.rgb, luminanceWeighting);
  
  lowp vec4 desat = vec4(vec3(luminance), 1.0);
  
  //overlay
  lowp vec4 outputColor = vec4(
                                 (desat.r < 0.5 ? (2.0 * desat.r * filterColor.r) : (1.0 - 2.0 * (1.0 - desat.r) * (1.0 - filterColor.r))),
                                 (desat.g < 0.5 ? (2.0 * desat.g * filterColor.g) : (1.0 - 2.0 * (1.0 - desat.g) * (1.0 - filterColor.g))),
                                 (desat.b < 0.5 ? (2.0 * desat.b * filterColor.b) : (1.0 - 2.0 * (1.0 - desat.b) * (1.0 - filterColor.b))),
                                 1.0
                                 );
  
  //which is better, or are they equal?
  gl_FragColor = vec4( mix(textureColor.rgb, outputColor.rgb, intensity), textureColor.a);
 }
);
#else
NSString *const kGPUMonochromeFragmentShaderString = SHADER_STRING
(
 varying vec2 textureCoordinate;
 
 uniform sampler2D inputImageTexture;
 uniform float intensity;
 uniform vec3 filterColor;
 
 const vec3 luminanceWeighting = vec3(0.2125, 0.7154, 0.0721);
 
 void main()
 {
     //desat, then apply overlay blend
     vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);
     float luminance = dot(textureColor.rgb, luminanceWeighting);
     
     vec4 desat = vec4(vec3(luminance), 1.0);
     
     //overlay
     vec4 outputColor = vec4(
                                  (desat.r < 0.5 ? (2.0 * desat.r * filterColor.r) : (1.0 - 2.0 * (1.0 - desat.r) * (1.0 - filterColor.r))),
                                  (desat.g < 0.5 ? (2.0 * desat.g * filterColor.g) : (1.0 - 2.0 * (1.0 - desat.g) * (1.0 - filterColor.g))),
                                  (desat.b < 0.5 ? (2.0 * desat.b * filterColor.b) : (1.0 - 2.0 * (1.0 - desat.b) * (1.0 - filterColor.b))),
                                  1.0
                                  );
     
     //which is better, or are they equal?
     gl_FragColor = vec4( mix(textureColor.rgb, outputColor.rgb, intensity), textureColor.a);
 }
);
#endif
/********************************************************************************************/
//@Author:猿说编程
//@Blog(个人博客地址): www.codersrc.com
//@File:IOS – OpenGL ES 调节图像单色 GPUImageMonochromeFilter
//@Time:2022/03/18 07:30
//@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 kGPUMonochromeFragmentShaderString = SHADER_STRING
(
 precision lowp float;
 
 varying highp vec2 textureCoordinate;
 
 uniform sampler2D inputImageTexture;
 uniform float intensity;
 uniform vec3 filterColor;
 
 const mediump vec3 luminanceWeighting = vec3(0.2125, 0.7154, 0.0721);
 
 void main()
 {
  //desat, then apply overlay blend
  lowp vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);
  float luminance = dot(textureColor.rgb, luminanceWeighting);
  
  lowp vec4 desat = vec4(vec3(luminance), 1.0);
  
  //overlay
  lowp vec4 outputColor = vec4(
                                 (desat.r < 0.5 ? (2.0 * desat.r * filterColor.r) : (1.0 - 2.0 * (1.0 - desat.r) * (1.0 - filterColor.r))),
                                 (desat.g < 0.5 ? (2.0 * desat.g * filterColor.g) : (1.0 - 2.0 * (1.0 - desat.g) * (1.0 - filterColor.g))),
                                 (desat.b < 0.5 ? (2.0 * desat.b * filterColor.b) : (1.0 - 2.0 * (1.0 - desat.b) * (1.0 - filterColor.b))),
                                 1.0
                                 );
  
  //which is better, or are they equal?
  gl_FragColor = vec4( mix(textureColor.rgb, outputColor.rgb, intensity), textureColor.a);
 }
);
#else
NSString *const kGPUMonochromeFragmentShaderString = SHADER_STRING
(
 varying vec2 textureCoordinate;
 
 uniform sampler2D inputImageTexture;
 uniform float intensity;
 uniform vec3 filterColor;
 
 const vec3 luminanceWeighting = vec3(0.2125, 0.7154, 0.0721);
 
 void main()
 {
     //desat, then apply overlay blend
     vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);
     float luminance = dot(textureColor.rgb, luminanceWeighting);
     
     vec4 desat = vec4(vec3(luminance), 1.0);
     
     //overlay
     vec4 outputColor = vec4(
                                  (desat.r < 0.5 ? (2.0 * desat.r * filterColor.r) : (1.0 - 2.0 * (1.0 - desat.r) * (1.0 - filterColor.r))),
                                  (desat.g < 0.5 ? (2.0 * desat.g * filterColor.g) : (1.0 - 2.0 * (1.0 - desat.g) * (1.0 - filterColor.g))),
                                  (desat.b < 0.5 ? (2.0 * desat.b * filterColor.b) : (1.0 - 2.0 * (1.0 - desat.b) * (1.0 - filterColor.b))),
                                  1.0
                                  );
     
     //which is better, or are they equal?
     gl_FragColor = vec4( mix(textureColor.rgb, outputColor.rgb, intensity), textureColor.a);
 }
);
#endif

/********************************************************************************************/
//@Author:猿说编程
//@Blog(个人博客地址): www.codersrc.com
//@File:IOS – OpenGL ES 调节图像单色 GPUImageMonochromeFilter
//@Time:2022/03/18 07:30
//@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 kGPUMonochromeFragmentShaderString = SHADER_STRING
(
 precision lowp float;
 
 varying highp vec2 textureCoordinate;
 
 uniform sampler2D inputImageTexture;
 uniform float intensity;
 uniform vec3 filterColor;
 
 const mediump vec3 luminanceWeighting = vec3(0.2125, 0.7154, 0.0721);
 
 void main()
 {
	//desat, then apply overlay blend
	lowp vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);
	float luminance = dot(textureColor.rgb, luminanceWeighting);
	
	lowp vec4 desat = vec4(vec3(luminance), 1.0);
	
	//overlay
	lowp vec4 outputColor = vec4(
                                 (desat.r < 0.5 ? (2.0 * desat.r * filterColor.r) : (1.0 - 2.0 * (1.0 - desat.r) * (1.0 - filterColor.r))),
                                 (desat.g < 0.5 ? (2.0 * desat.g * filterColor.g) : (1.0 - 2.0 * (1.0 - desat.g) * (1.0 - filterColor.g))),
                                 (desat.b < 0.5 ? (2.0 * desat.b * filterColor.b) : (1.0 - 2.0 * (1.0 - desat.b) * (1.0 - filterColor.b))),
                                 1.0
                                 );
	
	//which is better, or are they equal?
	gl_FragColor = vec4( mix(textureColor.rgb, outputColor.rgb, intensity), textureColor.a);
 }
);
#else
NSString *const kGPUMonochromeFragmentShaderString = SHADER_STRING
(
 varying vec2 textureCoordinate;
 
 uniform sampler2D inputImageTexture;
 uniform float intensity;
 uniform vec3 filterColor;
 
 const vec3 luminanceWeighting = vec3(0.2125, 0.7154, 0.0721);
 
 void main()
 {
     //desat, then apply overlay blend
     vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);
     float luminance = dot(textureColor.rgb, luminanceWeighting);
     
     vec4 desat = vec4(vec3(luminance), 1.0);
     
     //overlay
     vec4 outputColor = vec4(
                                  (desat.r < 0.5 ? (2.0 * desat.r * filterColor.r) : (1.0 - 2.0 * (1.0 - desat.r) * (1.0 - filterColor.r))),
                                  (desat.g < 0.5 ? (2.0 * desat.g * filterColor.g) : (1.0 - 2.0 * (1.0 - desat.g) * (1.0 - filterColor.g))),
                                  (desat.b < 0.5 ? (2.0 * desat.b * filterColor.b) : (1.0 - 2.0 * (1.0 - desat.b) * (1.0 - filterColor.b))),
                                  1.0
                                  );
     
     //which is better, or are they equal?
     gl_FragColor = vec4( mix(textureColor.rgb, outputColor.rgb, intensity), textureColor.a);
 }
);
#endif

二.效果演示

三.源码下载

下载地址：IOS – OpenGL ES 调节图像单色 GPUImageMonochromeFilter

四.猜你喜欢

• IOS – OPenGL ES 设置图像亮度 GPUImageBrightnessFilter
• IOS – OPenGL ES 调节图像曝光度 GPUImageExposureFilter
• IOS – OpenGL ES 调节图像对比度 GPUImageContrastFilter
• IOS – OPenGL ES 调节图像饱和度 GPUImageSaturationFilter
• IOS – OPenGL ES 调节图像伽马线 GPUImageGammaFilter
• IOS – OpenGL ES 调节图像反色 GPUImageColorInvertFilter
• IOS – OpenGL ES 调节图像褐色 GPUImageSepiaFilter
• IOS – OpenGL ES 调节图像灰色 GPUImageGrayscaleFilter
• IOS – OpenGL ES 调节图像单色 GPUImageMonochromeFilter

ChatGPT 3.5 国内中文镜像站免费使用啦