iOS capture image form GPUImage - ios

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];
}