How to get AVCaptureStillImageOutput same aspect ratio as the AVCaptureVideoPreviewLayer? - ios

Question

I'm capturing an image using AVFoundation. I'm using AVCaptureVideoPreviewLayer to display the camera feed on screen. This preview layer's frame gets the bounds of a UIView with dynamic dimensions:
AVCaptureVideoPreviewLayer *previewLayer = [[AVCaptureVideoPreviewLayer alloc] initWithSession:session];
[previewLayer setVideoGravity:AVLayerVideoGravityResizeAspectFill];
CALayer *rootLayer = [self.cameraFeedView layer];
[rootLayer setMasksToBounds:YES];
CGRect frame = self.cameraFeedView.frame;
[previewLayer setFrame:frame];
previewLayer.frame = rootLayer.bounds;
[rootLayer insertSublayer:previewLayer atIndex:0];
And I'm using AVCaptureStillImageOutput to capture an image:
AVCaptureStillImageOutput *stillImageOutput = [[AVCaptureStillImageOutput alloc] init];
[stillImageOutput captureStillImageAsynchronouslyFromConnection:videoConnection
completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
if (imageDataSampleBuffer != NULL) {
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
UIImage *capturedImage = [UIImage imageWithData:imageData];
}
}];
My problem is that the captured image is at the size of the iPhone camera (1280x960 - front camera), but I need it to be the same aspect ratio as the preview layer. For example, if the size of the preview layer is 150x100, I need the captured image to be 960x640. Is there any solution for this?

Answer 1

I also enter counter the same problem. You have to crop or resize output still image. But you should notice that output still`s scale and image orientation.
preview layer square frame
CGFloat width = CGRectGetWidth(self.view.bounds);
[self.captureVideoPreviewLayer setFrame:CGRectMake(0, 0, width, width)];
[self.cameraView.layer addSublayer:self.captureVideoPreviewLayer];
calculate cropped image`s frame
[self.captureStillImageOutput captureStillImageAsynchronouslyFromConnection:captureConnection completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error) {
NSData *data = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:data];
CGRect cropRect = CGRectMake((image.size.height - image.size.width) / 2, 0, image.size.width, image.size.width);
CGImageRef imageRef = CGImageCreateWithImageInRect([image CGImage], cropRect);
UIImage *croppedImage = [UIImage imageWithCGImage:imageRef scale:image.scale orientation:image.imageOrientation]; // always UIImageOrientationRight
CGImageRelease(imageRef);
}];