189 8069 5689
目录
创新互联建站服务项目包括江城网站建设、江城网站制作、江城网页制作以及江城网络营销策划等。多年来，我们专注于互联网行业，利用自身积累的技术优势、行业经验、深度合作伙伴关系等，向广大中小型企业、政府机构等提供互联网行业的解决方案，江城网站推广取得了明显的社会效益与经济效益。目前，我们服务的客户以成都为中心已经辐射到江城省份的部分城市，未来相信会继续扩大服务区域并继续获得客户的支持与信任！
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
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.
GPUImageThresholdSketchFilter 属于 GPUImage 图像视觉效果相关，用于图像阀值素描，形成有噪点的素描。shader 源码如下：
/******************************************************************************************/
//@Author:猿说编程
//@Blog(个人博客地址): www.codersrc.com
//@File:IOS – OpenGL ES GPUImage GPUImageThresholdSketchFilter
//@Time:2022/07/02 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 kGPUImageThresholdSketchFragmentShaderString = 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 lowp float threshold;
uniform float edgeStrength;
const highp vec3 W = vec3(0.2125, 0.7154, 0.0721);
void main()
{
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)) * edgeStrength);
mag = step(threshold, mag);
mag = 1.0 - mag;
gl_FragColor = vec4(vec3(mag), 1.0);
}
);
#else
NSString *const kGPUImageThresholdSketchFragmentShaderString = 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 threshold;
uniform float edgeStrength;
const vec3 W = vec3(0.2125, 0.7154, 0.0721);
void main()
{
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 = 1.0 - length(vec2(h, v) * edgeStrength);
mag = step(threshold, mag);
gl_FragColor = vec4(vec3(mag), 1.0);
}
);
#endif
使用GPUImageThresholdSketchFilter**,**原图如下：
使用GPUImageThresholdSketchFilter 效果如下：
OpenGL ES Demo 下载地址 : IOS OpenGL ES GPUImage 图像阀值素描，形成有噪点的素描 GPUImageThresholdSketchFilter
本文由博客 - 猿说编程 猿说编程 发布！