图片滤镜

GPUImagePicture 用于已拍摄的图片加滤镜

demo下载地址：https://github.com/SXDgit/GPUImage_Picture

直接上代码：

- (UIImage *)imageProcessdUsingGPUImage:(UIImage *)imageToProcess {
    GPUImagePicture *stillImageSource = [[GPUImagePicture alloc]initWithImage:imageToProcess];
    // 设置滤镜
    GPUImageSepiaFilter *stillImageFilter = [[GPUImageSepiaFilter alloc]init];
    [stillImageSource addTarget:stillImageFilter];
    [stillImageFilter useNextFrameForImageCapture];
    [stillImageSource processImage];
    
    UIImage *currentFilteredVideoFrame = [stillImageFilter imageFromCurrentFramebuffer];
    return currentFilteredVideoFrame;
}

效果图：

image

处理图片的方法有多种：CPU、CoreImage、GPUImage
处理效率（性能）：CPU >= GPUImage > CoreImage

具体可参考：https://blog.csdn.net/xoxo_x/article/details/53507016

GPUImageStillCamera 用于实时拍摄照片加滤镜

demo下载地址：https://github.com/SXDgit/GPUImage_StillCamera

直接上代码：

- (void)configGPUImageView {
    // 可视的预览view
    GPUImageView *imageView = [[GPUImageView alloc]initWithFrame:self.view.frame];
    imageView.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
    imageView.fillMode = kGPUImageFillModePreserveAspectRatio;
    self.view = imageView;
    
    // 创建滤镜
    self.filter = [[GPUImageSketchFilter alloc]init];
    
    // 创建Camera
    self.stillCamera = [[GPUImageStillCamera alloc]initWithSessionPreset:AVCaptureSessionPreset640x480 cameraPosition:AVCaptureDevicePositionBack];
    _stillCamera.outputImageOrientation = UIInterfaceOrientationPortrait;
    
    [_stillCamera addTarget:_filter];
    [_filter addTarget:imageView];
    [_stillCamera startCameraCapture];
}

// 拍摄
- (void)buttonAction {
    [_stillCamera capturePhotoAsJPEGProcessedUpToFilter:_filter withCompletionHandler:^(NSData *processedJPEG, NSError *error) {
        ALAssetsLibrary *library = [[ALAssetsLibrary alloc]init];
        [library writeImageDataToSavedPhotosAlbum:processedJPEG metadata:self.stillCamera.currentCaptureMetadata completionBlock:^(NSURL *assetURL, NSError *error) {
            if (error) {
                NSLog(@"ERROR: failed");
            }else {
                NSLog(@"SUCCESS: saved");
            }
        }];
    }];
}

效果图：

image