GPUimage实时滤镜的实现

　　GPUIMAGE中GPUImageStillCamera可以调用系统相机，并实现实时滤镜，但是我没有找到相机全屏的方法，望知道的说一下

GPUImageStillCamera继承自GPUImageVideoCamera类，添加了捕获照片的功能。

GPUImageVideoCamera

初始化方法：

- (id)initWithSessionPreset:(NSString *)sessionPreset cameraPosition:(AVCaptureDevicePosition)cameraPosition

sessionPreset是相机拍摄时的分辨率。它的值如下

AVCaptureSessionPresetPhoto AVCaptureSessionPresetHigh AVCaptureSessionPresetMedium AVCaptureSessionPresetLow AVCaptureSessionPreset320x240 AVCaptureSessionPreset352x288 AVCaptureSessionPreset640x480 AVCaptureSessionPreset960x540 AVCaptureSessionPreset1280x720 AVCaptureSessionPreset1920x1080 AVCaptureSessionPreset3840x2160 AVCaptureSessionPresetiFrame960x540 AVCaptureSessionPresetiFrame1280x720 AVCaptureSessionPresetInputPriority

 

cameraPosition相机设备，分为前后 

AVCaptureDevicePositionFront AVCaptureDevicePositionBack

 

 

- (void)startCameraCapture;开始捕获

- (void)stopCameraCapture;停止捕获

- (void)rotateCamera;切换前后摄像头

 

　　添加实时滤镜

定义GPUImageStillCamera对象

mCamera = [[GPUImageStillCamera alloc] initWithSessionPreset:AVCaptureSessionPresetPhoto cameraPosition:AVCaptureDevicePositionBack];
    _isBack = YES;
//    _mCamera.horizontallyMirrorRearFacingCamera = NO;
//    _mCamera.horizontallyMirrorFrontFacingCamera = YES;
    _mCamera.outputImageOrientation = UIInterfaceOrientationPortrait;

 

定义要应用的滤镜

_mFilter = [[FWAmaroFilter alloc] init];

 

 

 定义GPUImageView对象，将GPUImageStillCamera对象捕获的图像打印在GPUImageView的层。

    _mGPUImgView = [[GPUImageView alloc]initWithFrame:CGRectMake(0, 0, 320, 426)];

 

添加滤镜

    [_mCamera addTarget:_mFilter];

 

添加显示

    [_mFilter addTarget:_mGPUImgView];

 

开始捕获

    [_mCamera startCameraCapture];

 

    [self.view addSubview:_mGPUImgView];

 

到此为止。实时滤镜已经实现

 

实现拍照

-(void)takePhoto{
    [_mCamera capturePhotoAsJPEGProcessedUpToFilter:_mFilter withCompletionHandler:^(NSData *processedJPEG, NSError *error){
        [[PHPhotoLibrary sharedPhotoLibrary] performChanges:^{
        [[PHAssetCreationRequest creationRequestForAsset] addResourceWithType:PHAssetResourceTypePhoto data:processedJPEG options:nil];
        } completionHandler:^(BOOL success, NSError * _Nullable error) {
            
        }];
    }];
}