IOS – OpenGL ES 设置图像锐化 GPUImageSharpenFilter

一.简介
二.效果演示
三.源码下载
四.猜你喜欢

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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.

**GPUImageSharpenFilter 属于 GPUImage 图像处理相关，用来处理图像锐化效果，**shader 源码如下：

/******************************************************************************************/
//@Author:猿说编程
//@Blog(个人博客地址): www.codersrc.com
//@File:IOS – OpenGL ES 设置图像锐化 GPUImageSharpenFilter
//@Time:2022/04/17 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！
/******************************************************************************************/NSString \*const kGPUImageSharpenVertexShaderString = SHADER_STRING
(
attribute vec4 position;
attribute vec4 inputTextureCoordinate;uniform float imageWidthFactor;
uniform float imageHeightFactor;
uniform float sharpness;varying vec2 textureCoordinate;
varying vec2 leftTextureCoordinate;
varying vec2 rightTextureCoordinate;
varying vec2 topTextureCoordinate;
varying vec2 bottomTextureCoordinate;varying float centerMultiplier;
varying float edgeMultiplier;void main()
{
gl_Position = position;vec2 widthStep = vec2(imageWidthFactor, 0.0);vec2 heightStep = vec2(0.0, imageHeightFactor);textureCoordinate = inputTextureCoordinate.xy;leftTextureCoordinate = inputTextureCoordinate.xy - widthStep;rightTextureCoordinate = inputTextureCoordinate.xy + widthStep;topTextureCoordinate = inputTextureCoordinate.xy + heightStep;bottomTextureCoordinate = inputTextureCoordinate.xy - heightStep;centerMultiplier = 1.0 + 4.0 * sharpness;edgeMultiplier = sharpness;}
);#if TARGET_IPHONE_SIMULATOR || TARGET_OS_IPHONE
NSString \*const kGPUImageSharpenFragmentShaderString = SHADER_STRING
(
precision highp float;varying highp vec2 textureCoordinate;
varying highp vec2 leftTextureCoordinate;
varying highp vec2 rightTextureCoordinate;
varying highp vec2 topTextureCoordinate;
varying highp vec2 bottomTextureCoordinate;varying highp float centerMultiplier;
varying highp float edgeMultiplier;uniform sampler2D inputImageTexture;void main()
{
mediump vec3 textureColor = texture2D(inputImageTexture, textureCoordinate).rgb;
mediump vec3 leftTextureColor = texture2D(inputImageTexture, leftTextureCoordinate).rgb;
mediump vec3 rightTextureColor = texture2D(inputImageTexture, rightTextureCoordinate).rgb;
mediump vec3 topTextureColor = texture2D(inputImageTexture, topTextureCoordinate).rgb;
mediump vec3 bottomTextureColor = texture2D(inputImageTexture, bottomTextureCoordinate).rgb;gl_FragColor = vec4((textureColor * centerMultiplier - (leftTextureColor * edgeMultiplier + rightTextureColor * edgeMultiplier + topTextureColor * edgeMultiplier + bottomTextureColor * edgeMultiplier)), texture2D(inputImageTexture, bottomTextureCoordinate).w);}
);
#else
NSString \*const kGPUImageSharpenFragmentShaderString = SHADER_STRING
(
varying vec2 textureCoordinate;
varying vec2 leftTextureCoordinate;
varying vec2 rightTextureCoordinate;
varying vec2 topTextureCoordinate;
varying vec2 bottomTextureCoordinate;varying float centerMultiplier;
varying float edgeMultiplier;uniform sampler2D inputImageTexture;void main()
{
vec3 textureColor = texture2D(inputImageTexture, textureCoordinate).rgb;
vec3 leftTextureColor = texture2D(inputImageTexture, leftTextureCoordinate).rgb;
vec3 rightTextureColor = texture2D(inputImageTexture, rightTextureCoordinate).rgb;
vec3 topTextureColor = texture2D(inputImageTexture, topTextureCoordinate).rgb;
vec3 bottomTextureColor = texture2D(inputImageTexture, bottomTextureCoordinate).rgb;gl_FragColor = vec4((textureColor * centerMultiplier - (leftTextureColor * edgeMultiplier + rightTextureColor * edgeMultiplier + topTextureColor * edgeMultiplier + bottomTextureColor * edgeMultiplier)), texture2D(inputImageTexture, bottomTextureCoordinate).w);}
);
#endif