iOS捕获图像形式GPUImage

Question

I am trying to capture an image with an app that uses GPUImage. I have the camera set up like this

self.videoCamera = [[GPUImageVideoCamera alloc]
                    initWithSessionPreset:AVCaptureSessionPresetHigh
                    cameraPosition:AVCaptureDevicePositionBack];
_videoCamera.outputImageOrientation = UIInterfaceOrientationPortrait;
[_videoCamera startCameraCapture];
[_videoCamera addTarget:sample1ImageView];

and i use a custom filter:

radFilter = [[GPUImageCustomFilter alloc] init];
[_videoCamera addTarget:cusFilter];
[cusFilter addTarget:imageView];

I then use this code for the camera capture:

[_videoCamera pauseCameraCapture];
[radFilter forceProcessingAtSize:CGSizeMake(600, 600)];
[radFilter useNextFrameForImageCapture];
UIImage* capturedImage = [radFilter imageFromCurrentFramebuffer];
UIImageWriteToSavedPhotosAlbum(capturedImage, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
[_videoCamera resumeCameraCapture];

and all i get is white pictures, with rgb 0,0,0. I tried saving both in an IBAction and in a rac_signalForControlEvents,i used dispatch but nothing changed. Can anyone tell me what am i doing wrong?

Thank you, Alex

Answer 1

try using GPUImageStillCamera like these..

in your .h file..

GPUImageStillCamera *stillCamera;
GPUImageView * filterView;

in your .m files viewdidload..

selectedFilter = [[GPUImageFilter alloc]init];
filterView=[[GPUImageView alloc]init];

stillCamera=[[GPUImageStillCamera alloc]initWithSessionPreset:AVCaptureSessionPresetPhoto cameraPosition:AVCaptureDevicePositionFront];
stillCamera.outputImageOrientation = UIInterfaceOrientationPortrait;
[stillCamera addTarget:selectedFilter];
[selectedFilter addTarget:filterView];
[stillCamera startCameraCapture];

on the UIButtons click event for capturing image do these,i hope it helps..

[stillCamera capturePhotoAsImageProcessedUpToFilter:selectedFilter withCompletionHandler:^(UIImage *processedImage, NSError *error)
 {
        UIImageWriteToSavedPhotosAlbum(processedImage, self, nil, nil);
 }];

Answer 2

You can use this code to capture the image.

- (UIImage *) screenshot {
    UIGraphicsBeginImageContextWithOptions(self.view.bounds.size, NO, [UIScreen mainScreen].scale);

    [self.view drawViewHierarchyInRect:self.view.bounds afterScreenUpdates:YES];

    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}

- (IBAction)btnCaptureClicked:(id)sender
{
    [videoCamera pauseCameraCapture];
    [filter useNextFrameForImageCapture];
    //[filter imageFromCurrentFramebuffer];
    UIImage *capturedImage= [self screenshot];
    if(capturedImage != nil)
    {
        UIImageWriteToSavedPhotosAlbum(capturedImage, self, @selector(image:didFinishSavingWithError:contextInfo:), nil);
    }
    [videoCamera resumeCameraCapture];
}