GPUImage處理圖片(濾鏡)

　　GPUImage 是基於 GPU 處理圖像的一個開源庫, 提供了各類圖像處理濾鏡,例如調 亮度/飽和度/曝光度/白平衡/銳化等濾鏡.

而且支持照相機/攝像機 的實時濾鏡.

     GPUImage採用鏈式方式來處理畫面,經過addTarget:方法爲鏈條添加每一個環節的對象，處理完一個target,就會把上一個環節處理好的圖像數據傳遞下一個target去處理，稱爲GPUImage處理鏈.

 

https://github.com/BradLarson/GPUImage

 圖片濾鏡

//調整圖像的對比度
- (void)changeContrast{
    //對比度
//    GPUImageContrastFilter *filter = [[GPUImageContrastFilter alloc]init];
//    filter.contrast = self.slider.value; 
     //飽和度
//    GPUImageSaturationFilter *filter = [[GPUImageSaturationFilter alloc]init];
//    filter.saturation = self.slider.value;
     //曝光度
//    GPUImageExposureFilter *filter = [[GPUImageExposureFilter alloc] init];
//    filter.exposure = self.slider.value;
     //色溫(白平衡)
    GPUImageWhiteBalanceFilter *filter = [[GPUImageWhiteBalanceFilter alloc] init];
    filter.temperature = self.slider.value;
     filter.tint = 0.0;

    //設置要渲染的區域
    [filter forceProcessingAtSize:_image.size];
    
    //獲取 GPU 圖片
    GPUImagePicture *pic = [[GPUImagePicture alloc]initWithImage:_image];
    //添加濾鏡
    [pic addTarget:filter];
    //開始渲染
    [pic processImage];
    //(須要調用一下? why?)
    [filter useNextFrameForImageCapture];
    //獲取渲染後的圖片
    UIImage *newImage = [filter imageFromCurrentFramebuffer];
    
    self.imageView.image = newImage;
    
    
}

　　

 實時相機濾鏡

//建立相機(注意:當前vc需持有camera, 不然會提早釋放)
    camera = [[GPUImageVideoCamera alloc]initWithSessionPreset:AVCaptureSessionPresetHigh cameraPosition:AVCaptureDevicePositionFront];
    camera.outputImageOrientation = UIInterfaceOrientationPortrait;
    
    //建立最終預覽視圖 view
    GPUImageView *cameraView = [[GPUImageView alloc]initWithFrame:self.view.frame];
    [self.view insertSubview:cameraView atIndex:0];
    
 
    //建立濾鏡組合: 磨皮,美白
    GPUImageFilterGroup *groupFilter = [[GPUImageFilterGroup alloc]init];
    //磨皮濾鏡
    GPUImageBilateralFilter *bilateralFilter = [[GPUImageBilateralFilter alloc]init];
    [groupFilter addTarget:bilateralFilter];
    //美白濾鏡
    GPUImageBrightnessFilter *brightFilter = [[GPUImageBrightnessFilter alloc]init];
    [groupFilter addTarget:brightFilter];
    //設置濾鏡組鏈
    [bilateralFilter addTarget:brightFilter];
    [groupFilter setInitialFilters:@[bilateralFilter]];
    groupFilter.terminalFilter = brightFilter;
    //設置 GPUImage 處理鏈,從數據源->濾鏡->最終頁面效果
    [camera addTarget:groupFilter];
    [groupFilter addTarget:cameraView];
    
    //相機開始捕獲
    [camera startCameraCapture];

 

 

 

參考:

//濾鏡效果

http://blog.csdn.net/gaojq_ios/article/details/46926559

//實時濾鏡(相機)

https://www.jianshu.com/p/b1d3ef7fdf7a

https://www.jianshu.com/p/2ce9b63ecfef 

http://blog.csdn.net/xoxo_x/article/details/58357978

博客:(總結)

 http://blog.csdn.net/xoxo_x/article/details/52695032

GPUImage 原理

http://blog.csdn.net/qq_29846663/article/details/53707482

GPUImage全部濾鏡介紹

http://www.360doc.com/content/15/0907/10/19175681_497418716.shtml