Scaled and merged image not saving properly (iOS) - objective-c

Question

I've taken a screenshot of a certain part of my window, then scaled it down and merged with an image also scaled down. The problem is that when I go to its path, there's a PNG file saved with 0KB, so the image isn't saved. Any idea? Thanks!
Here's my current code:
//Save images
- (void) saveimages {
//Save small one (mini)
NSString *docDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0];
UIGraphicsBeginImageContextWithOptions((myImageView.bounds.size), NO, 0.5);
[myImageView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *mini = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
float miniVW = VView.image.size.width / 2;
float miniVH = VView.image.size.height / 2;
UIImage *miniV = [self imageWithImage:certain.image convertToSize:CGSizeMake(miniVW, miniVH)];
UIImage *miniTotal = [self mergeIMG:miniV:mini];
NSString *pngFilePath = [NSString stringWithFormat:#"%#/mini%i.png",docDir,number];
NSData *data = [NSData dataWithData:UIImagePNGRepresentation(miniTotal)];
[data writeToFile:pngFilePath atomically:YES];
}
//Merge two images in one
- (UIImage *) mergeIMG:(UIImage *)VextImg:(UIImage *)VintImg {
//Create a new image from two
CGSize newSize = CGSizeMake(VintImg.size.width, VintImg.size.width);
[VintImg drawInRect:CGRectMake(0, 0, newSize.width, newSize.height)];
[VextImg drawInRect:CGRectMake(0, 0, newSize.width, newSize.height) blendMode:kCGBlendModeNormal alpha:1.0];
UIImage *finalIMG = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return finalIMG;
}
//Scale image
- (UIImage *) imageWithImage:(UIImage *)image convertToSize:(CGSize)size {
//Change size
UIGraphicsBeginImageContext(size);
[image drawInRect:CGRectMake(0, 0, size.width, size.height)];
UIImage *destImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();
return destImage;
}

Answer 1

mergeImage does not call UIGraphicsBeginImageContextWithOptions