GPUImage simple filter implementation

GPUImage is currently the most mainstream open source framework for filters, and there is no one. The author BradLarson encapsulates the image processing unit based on openGL and provides the GPUImageFilter base class. With the shader, it is not a problem to get the commonly used filters.

1. Installation

(1): First download GPUImage https://github.com/BradLarson/GPUImage

(2): After decompression, in the framework directory, open the GPUImage.xcodeproj project

(3) Because GPUImage is an open source library, you need to generate a static library yourself (the previous stupid way to add the entire project to the project, which caused unnecessary trouble in use)

(4): Run the project (generate lib for real machine and simulator)

(5) Click libGPUImage.a under Products, right click, show in finder to merge the two libs (for details, see the blog post on creating static libraries)

(6) Extract all the header files contained in the GPUImage.h file into the header file

Two, create a project for using GPUImage

1. Create a project

2. Add the header folder and libGPUImage.a to the project

The directory structure is:

3. Write test code

@implementation ViewController


- (void)viewDidLoad

{

    [super viewDidLoad];

    UIImage * inputImage = [UIImage imageNamed:@"k"];

    //使用黑白素描滤镜

     GPUImageSketchFilter *disFilter = [[GPUImageSketchFilter alloc] init];



    //设置要渲染的区域

    [disFilter forceProcessingAtSize:inputImage.size];

    [disFilter useNextFrameForImageCapture];



    //获取数据源

    GPUImagePicture *stillImageSource = [[GPUImagePicture alloc]initWithImage:inputImage];


    //添加上滤镜

    [stillImageSource addTarget:disFilter];

    //开始渲染

    [stillImageSource processImage];

    //获取渲染后的图片

    UIImage *newImage = [disFilter imageFromCurrentFramebuffer];

    //加载出来

    UIImageView *imageView = [[UIImageView alloc] initWithImage:newImage];

    imageView.frame = CGRectMake(50,50,inputImage.size.width ,inputImage.size.height);

    [self.view addSubview:imageView];

}

4. Run the eyesight
picture

The picture effect after filtering.

Three, several concepts in GPUImage

⁃ output is the output source

⁃ intput is the input source

⁃ filter is a filter

 28 #import "GPUImageBrightnessFilter.h"                //亮度
 29 #import "GPUImageExposureFilter.h"                  //曝光
 30 #import "GPUImageContrastFilter.h"                  //对比度
 31 #import "GPUImageSaturationFilter.h"                //饱和度
 32 #import "GPUImageGammaFilter.h"                     //伽马线
 33 #import "GPUImageColorInvertFilter.h"               //反色
 34 #import "GPUImageSepiaFilter.h"                     //褐色（怀旧）
 35 #import "GPUImageLevelsFilter.h"                    //色阶
 36 #import "GPUImageGrayscaleFilter.h"                 //灰度
 37 #import "GPUImageHistogramFilter.h"                 //色彩直方图，显示在图片上
 38 #import "GPUImageHistogramGenerator.h"              //色彩直方图
 39 #import "GPUImageRGBFilter.h"                       //RGB
 40 #import "GPUImageToneCurveFilter.h"                 //色调曲线
 41 #import "GPUImageMonochromeFilter.h"                //单色
 42 #import "GPUImageOpacityFilter.h"                   //不透明度
 43 #import "GPUImageHighlightShadowFilter.h"           //提亮阴影
 44 #import "GPUImageFalseColorFilter.h"                //色彩替换（替换亮部和暗部色彩）
 45 #import "GPUImageHueFilter.h"                       //色度
 46 #import "GPUImageChromaKeyFilter.h"                 //色度键
 47 #import "GPUImageWhiteBalanceFilter.h"              //白平横
 48 #import "GPUImageAverageColor.h"                    //像素平均色值
 49 #import "GPUImageSolidColorGenerator.h"             //纯色
 50 #import "GPUImageLuminosity.h"                      //亮度平均
 51 #import "GPUImageAverageLuminanceThresholdFilter.h" //像素色值亮度平均，图像黑白（有类似漫画效果）
 52 
 53 #import "GPUImageLookupFilter.h"                    //lookup 色彩调整
 54 #import "GPUImageAmatorkaFilter.h"                  //Amatorka lookup
 55 #import "GPUImageMissEtikateFilter.h"               //MissEtikate lookup
 56 #import "GPUImageSoftEleganceFilter.h"              //SoftElegance lookup

 61 #pragma mark - 图像处理 Handle Image
 62 
 63 #import "GPUImageCrosshairGenerator.h"              //十字
 64 #import "GPUImageLineGenerator.h"                   //线条
 65 
 66 #import "GPUImageTransformFilter.h"                 //形状变化
 67 #import "GPUImageCropFilter.h"                      //剪裁
 68 #import "GPUImageSharpenFilter.h"                   //锐化
 69 #import "GPUImageUnsharpMaskFilter.h"               //反遮罩锐化
 70 
 71 #import "GPUImageFastBlurFilter.h"                  //模糊
 72 #import "GPUImageGaussianBlurFilter.h"              //高斯模糊
 73 #import "GPUImageGaussianSelectiveBlurFilter.h"     //高斯模糊，选择部分清晰
 74 #import "GPUImageBoxBlurFilter.h"                   //盒状模糊
 75 #import "GPUImageTiltShiftFilter.h"                 //条纹模糊，中间清晰，上下两端模糊
 76 #import "GPUImageMedianFilter.h"                    //中间值，有种稍微模糊边缘的效果
 77 #import "GPUImageBilateralFilter.h"                 //双边模糊
 78 #import "GPUImageErosionFilter.h"                   //侵蚀边缘模糊，变黑白
 79 #import "GPUImageRGBErosionFilter.h"                //RGB侵蚀边缘模糊，有色彩
 80 #import "GPUImageDilationFilter.h"                  //扩展边缘模糊，变黑白
 81 #import "GPUImageRGBDilationFilter.h"               //RGB扩展边缘模糊，有色彩
 82 #import "GPUImageOpeningFilter.h"                   //黑白色调模糊
 83 #import "GPUImageRGBOpeningFilter.h"                //彩色模糊
 84 #import "GPUImageClosingFilter.h"                   //黑白色调模糊，暗色会被提亮
 85 #import "GPUImageRGBClosingFilter.h"                //彩色模糊，暗色会被提亮
 86 #import "GPUImageLanczosResamplingFilter.h"         //Lanczos重取样，模糊效果
 87 #import "GPUImageNonMaximumSuppressionFilter.h"     //非最大抑制，只显示亮度最高的像素，其他为黑
 88 #import "GPUImageThresholdedNonMaximumSuppressionFilter.h" //与上相比，像素丢失更多
 89 
 90 #import "GPUImageSobelEdgeDetectionFilter.h"        //Sobel边缘检测算法(白边，黑内容，有点漫画的反色效果)
 91 #import "GPUImageCannyEdgeDetectionFilter.h"        //Canny边缘检测算法（比上更强烈的黑白对比度）
 92 #import "GPUImageThresholdEdgeDetectionFilter.h"    //阈值边缘检测（效果与上差别不大）
 93 #import "GPUImagePrewittEdgeDetectionFilter.h"      //普瑞维特(Prewitt)边缘检测(效果与Sobel差不多，貌似更平滑)
 94 #import "GPUImageXYDerivativeFilter.h"              //XYDerivative边缘检测，画面以蓝色为主，绿色为边缘，带彩色
 95 #import "GPUImageHarrisCornerDetectionFilter.h"     //Harris角点检测，会有绿色小十字显示在图片角点处
 96 #import "GPUImageNobleCornerDetectionFilter.h"      //Noble角点检测，检测点更多
 97 #import "GPUImageShiTomasiFeatureDetectionFilter.h" //ShiTomasi角点检测，与上差别不大
 98 #import "GPUImageMotionDetector.h"                  //动作检测
 99 #import "GPUImageHoughTransformLineDetector.h"      //线条检测
100 #import "GPUImageParallelCoordinateLineTransformFilter.h" //平行线检测
101 
102 #import "GPUImageLocalBinaryPatternFilter.h"        //图像黑白化，并有大量噪点
103 
104 #import "GPUImageLowPassFilter.h"                   //用于图像加亮
105 #import "GPUImageHighPassFilter.h"                  //图像低于某值时显示为黑
106 
107 
108 #pragma mark - 视觉效果 Visual Effect
109 
110 #import "GPUImageSketchFilter.h"                    //素描
111 #import "GPUImageThresholdSketchFilter.h"           //阀值素描，形成有噪点的素描
112 #import "GPUImageToonFilter.h"                      //卡通效果（黑色粗线描边）
113 #import "GPUImageSmoothToonFilter.h"                //相比上面的效果更细腻，上面是粗旷的画风
114 #import "GPUImageKuwaharaFilter.h"                  //桑原(Kuwahara)滤波,水粉画的模糊效果；处理时间比较长，慎用
115 
116 #import "GPUImageMosaicFilter.h"                    //黑白马赛克
117 #import "GPUImagePixellateFilter.h"                 //像素化
118 #import "GPUImagePolarPixellateFilter.h"            //同心圆像素化
119 #import "GPUImageCrosshatchFilter.h"                //交叉线阴影，形成黑白网状画面
120 #import "GPUImageColorPackingFilter.h"              //色彩丢失，模糊（类似监控摄像效果）
121 
122 #import "GPUImageVignetteFilter.h"                  //晕影，形成黑色圆形边缘，突出中间图像的效果
123 #import "GPUImageSwirlFilter.h"                     //漩涡，中间形成卷曲的画面
124 #import "GPUImageBulgeDistortionFilter.h"           //凸起失真，鱼眼效果
125 #import "GPUImagePinchDistortionFilter.h"           //收缩失真，凹面镜
126 #import "GPUImageStretchDistortionFilter.h"         //伸展失真，哈哈镜
127 #import "GPUImageGlassSphereFilter.h"               //水晶球效果
128 #import "GPUImageSphereRefractionFilter.h"          //球形折射，图形倒立
129     
130 #import "GPUImagePosterizeFilter.h"                 //色调分离，形成噪点效果
131 #import "GPUImageCGAColorspaceFilter.h"             //CGA色彩滤镜，形成黑、浅蓝、紫色块的画面
132 #import "GPUImagePerlinNoiseFilter.h"               //柏林噪点，花边噪点
133 #import "GPUImage3x3ConvolutionFilter.h"            //3x3卷积，高亮大色块变黑，加亮边缘、线条等
134 #import "GPUImageEmbossFilter.h"                    //浮雕效果，带有点3d的感觉
135 #import "GPUImagePolkaDotFilter.h"                  //像素圆点花样
136 #import "GPUImageHalftoneFilter.h"                  //点染,图像黑白化，由黑点构成原图的大致图形
137 
138 
139 #pragma mark - 混合模式 Blend
140 
141 #import "GPUImageMultiplyBlendFilter.h"             //通常用于创建阴影和深度效果
142 #import "GPUImageNormalBlendFilter.h"               //正常
143 #import "GPUImageAlphaBlendFilter.h"                //透明混合,通常用于在背景上应用前景的透明度
144 #import "GPUImageDissolveBlendFilter.h"             //溶解
145 #import "GPUImageOverlayBlendFilter.h"              //叠加,通常用于创建阴影效果
146 #import "GPUImageDarkenBlendFilter.h"               //加深混合,通常用于重叠类型
147 #import "GPUImageLightenBlendFilter.h"              //减淡混合,通常用于重叠类型
148 #import "GPUImageSourceOverBlendFilter.h"           //源混合
149 #import "GPUImageColorBurnBlendFilter.h"            //色彩加深混合
150 #import "GPUImageColorDodgeBlendFilter.h"           //色彩减淡混合
151 #import "GPUImageScreenBlendFilter.h"               //屏幕包裹,通常用于创建亮点和镜头眩光
152 #import "GPUImageExclusionBlendFilter.h"            //排除混合
153 #import "GPUImageDifferenceBlendFilter.h"           //差异混合,通常用于创建更多变动的颜色
154 #import "GPUImageSubtractBlendFilter.h"             //差值混合,通常用于创建两个图像之间的动画变暗模糊效果
155 #import "GPUImageHardLightBlendFilter.h"            //强光混合,通常用于创建阴影效果
156 #import "GPUImageSoftLightBlendFilter.h"            //柔光混合
157 #import "GPUImageChromaKeyBlendFilter.h"            //色度键混合
158 #import "GPUImageMaskFilter.h"                      //遮罩混合
159 #import "GPUImageHazeFilter.h"                      //朦胧加暗
160 #import "GPUImageLuminanceThresholdFilter.h"        //亮度阈
161 #import "GPUImageAdaptiveThresholdFilter.h"         //自适应阈值
162 #import "GPUImageAddBlendFilter.h"                  //通常用于创建两个图像之间的动画变亮模糊效果
163 #import "GPUImageDivideBlendFilter.h"               //通常用于创建两个图像之间的动画变暗模糊效果
164 
165 
166 #pragma mark - 尚不清楚
167 #import "GPUImageJFAVoroniFilter.h"
168 #import "GPUImageVoroniConsumerFilter.h"