Memory warnings/leaks - ios

Question

EDIT 1: This problem specially happens on iOS7.
I'm trying to crop an image that was already taken by the UIImagePickerController using some Core Graphics methods inside the imagePickerController method:
- (void)imagePickerController:(UIImagePickerController *)photoPicker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
UIImage *image = [info valueForKey:UIImagePickerControllerOriginalImage];
if(modeSelected == kModeTypeAutomatic){
//cropping image
if(image.imageOrientation == UIImageOrientationUp){
CGImageRef tmpImgRef = [image CGImage];
CGImageRef topImgRef = CGImageCreateWithImageInRect(tmpImgRef, CGRectMake(image.size.width/2, 0, image.size.width/2, image.size.height));
secondImage = [UIImage imageWithCGImage:topImgRef];
CGImageRelease(topImgRef);
}
else{
CGImageRef tmpImgRef = [image CGImage];
CGImageRef topImgRef = CGImageCreateWithImageInRect(tmpImgRef, CGRectMake(0, 0, image.size.width, image.size.height/2.0));
secondImage = [UIImage imageWithCGImage:topImgRef scale:image.scale orientation:UIImageOrientationRight];
CGImageRelease(topImgRef);
}
}
image = nil;
[photoPicker dismissViewControllerAnimated:NO completion:nil];
if (secondImage) {
[self performSegueWithIdentifier:#"SecondPicTakenSegue" sender:nil];
}
}
I made some allocations and memory leaks using Instrument, and I verified that the problem is inside this method.
Am I not releasing something here? Is something missing?
Thanks!

Answer 1

Hard to tell from that code snippet, but secondImage could be what's being leaked. No harm in explicitly setting it to nil in your dealloc method to see if that helps:
-(void)dealloc {
secondImage = nil;
}

Answer 2

This may be your issue (from the CGImage reference, under CGImageCreateWithImageInRect):
The resulting image retains a reference to the original image, which means you may release the original image after calling this function.
https://developer.apple.com/library/ios/documentation/graphicsimaging/reference/CGImage/Reference/reference.html#jumpTo_6
So you may want to try a CGImageRelease(tmpImgRef) since it sounds like you may be incrementing the reference count with that call to CGImageCreateWithImageInRect. I haven't tested this myself to ensure that this is the case, but perhaps worth a shot.