IOS – OpenGL ES 卡通效果（黑色粗線描邊） GPUImageToonFilter

阿新 • • 發佈：2022-05-26

一.簡介
二.效果演示
三.原始碼下載
四.猜你喜歡

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一.簡介

GPUImage 共 125 個濾鏡, 分為四類

1、Color adjustments : 31 filters , 顏色處理相關
2、Image processing : 40 filters , 影象處理相關.
3、Blending modes : 29 filters , 混合模式相關.
4、Visual effects : 25 filters , 視覺效果相關.

GPUImageToonFilter 屬於 GPUImage 影象處理相關，用來影象卡通效果（黑色粗線描邊），shader 原始碼如下：

******************************************************************************************/
//@Author:猿說程式設計
//@Blog(個人部落格地址): www.codersrc.com
//@File:IOS – OpenGL ES 卡通效果（黑色粗線描邊） GPUImageToonFilter
//@Time:2022/05/14 10:30
//@Motto:不積跬步無以至千里，不積小流無以成江海，程式人生的精彩需要堅持不懈地積累！
/******************************************************************************************/


#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE
NSString *const kGPUImageToonFragmentShaderString = SHADER_STRING
(
 precision highp float;

 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;

 uniform sampler2D inputImageTexture;

 uniform highp float intensity;
 uniform highp float threshold;
 uniform highp float quantizationLevels;

 const highp vec3 W = vec3(0.2125, 0.7154, 0.0721);

 void main()
 {
     vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);

     float bottomLeftIntensity = texture2D(inputImageTexture, bottomLeftTextureCoordinate).r;
     float topRightIntensity = texture2D(inputImageTexture, topRightTextureCoordinate).r;
     float topLeftIntensity = texture2D(inputImageTexture, topLeftTextureCoordinate).r;
     float bottomRightIntensity = texture2D(inputImageTexture, bottomRightTextureCoordinate).r;
     float leftIntensity = texture2D(inputImageTexture, leftTextureCoordinate).r;
     float rightIntensity = texture2D(inputImageTexture, rightTextureCoordinate).r;
     float bottomIntensity = texture2D(inputImageTexture, bottomTextureCoordinate).r;
     float topIntensity = texture2D(inputImageTexture, topTextureCoordinate).r;
     float h = -topLeftIntensity - 2.0 * topIntensity - topRightIntensity + bottomLeftIntensity + 2.0 * bottomIntensity + bottomRightIntensity;
     float v = -bottomLeftIntensity - 2.0 * leftIntensity - topLeftIntensity + bottomRightIntensity + 2.0 * rightIntensity + topRightIntensity;

     float mag = length(vec2(h, v));

     vec3 posterizedImageColor = floor((textureColor.rgb * quantizationLevels) + 0.5) / quantizationLevels;

     float thresholdTest = 1.0 - step(threshold, mag);

     gl_FragColor = vec4(posterizedImageColor * thresholdTest, textureColor.a);
 }
);
#else
NSString *const kGPUImageToonFragmentShaderString = SHADER_STRING
(
 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;

 uniform sampler2D inputImageTexture;

 uniform float intensity;
 uniform float threshold;
 uniform float quantizationLevels;

 const vec3 W = vec3(0.2125, 0.7154, 0.0721);

 void main()
 {
     vec4 textureColor = texture2D(inputImageTexture, textureCoordinate);

     float bottomLeftIntensity = texture2D(inputImageTexture, bottomLeftTextureCoordinate).r;
     float topRightIntensity = texture2D(inputImageTexture, topRightTextureCoordinate).r;
     float topLeftIntensity = texture2D(inputImageTexture, topLeftTextureCoordinate).r;
     float bottomRightIntensity = texture2D(inputImageTexture, bottomRightTextureCoordinate).r;
     float leftIntensity = texture2D(inputImageTexture, leftTextureCoordinate).r;
     float rightIntensity = texture2D(inputImageTexture, rightTextureCoordinate).r;
     float bottomIntensity = texture2D(inputImageTexture, bottomTextureCoordinate).r;
     float topIntensity = texture2D(inputImageTexture, topTextureCoordinate).r;
     float h = -topLeftIntensity - 2.0 * topIntensity - topRightIntensity + bottomLeftIntensity + 2.0 * bottomIntensity + bottomRightIntensity;
     float v = -bottomLeftIntensity - 2.0 * leftIntensity - topLeftIntensity + bottomRightIntensity + 2.0 * rightIntensity + topRightIntensity;

     float mag = length(vec2(h, v));

     vec3 posterizedImageColor = floor((textureColor.rgb * quantizationLevels) + 0.5) / quantizationLevels;

     float thresholdTest = 1.0 - step(threshold, mag);

     gl_FragColor = vec4(posterizedImageColor * thresholdTest, textureColor.a);
 }
);
#endif

二.效果演示

使用 GPUImageToonFilter 用來影象卡通效果（黑色粗線描邊）****，原圖：

**GPUImageToonFilter** 用來影象卡通效果（黑色粗線描邊）**，效果圖：**

三.原始碼下載

OpenGL ES Demo 下載地址 : IOS – OpenGL ES 設定影象卡通效果（黑色粗線描邊） GPUImageToonFilter