UIImage from CgImageRef while adding sticker

Question

UIImage *sticky = [UIImage imageNamed:@"Radio.png"];
[_imgViewSticky setImage:sticky];
CIImage *outputImage = [self.originalImage CIImage];
CIContext *context = [CIContext contextWithOptions:nil];
CGImageRef cgImg = [context createCGImage:outputImage fromRect:[outputImage extent]];
float widthRatio = [outputImage extent].size.width / 320;
float heighRatio = [outputImage extent].size.height / 480;
CGPoint cgStickyPoint = CGPointMake(_imgViewSticky.frame.origin.x * widthRatio, _imgViewSticky.frame.origin.y * heighRatio);

cgImg = [self setStickyForCGImage:cgImg withPosition:cgStickyPoint];

The last line returns a CGImageRef object.

And I'm assigning the value to final image like this:

UIImage *finalImage = [UIImage ImageWithCGImageRef:cgImg];

Yet I'm not getting the image. Any ideas why? Any Help is much appreciated.

Answer 1

I notice that your CIContext isn't receiving any drawing, which could be why you're not getting an image. I don't have a clear picture of what you want, but this code will superimpose one UIImage on top of another UIImage:

UIGraphicsBeginImageContextWithOptions(backgroundImage.size, NO, 0.0); //Create an image context
[backgroundImage drawInRect:CGRectMake(0, 0, backgroundImage.size.width, backgroundImage.size.height)]; //Draw the first UIImage
[stickerImage drawInRect:stickerRect]; //Draw the second UIImage wherever you want on top of the first image
UIImage *finalImage = UIGraphicsGetImageFromCurrentImageContext(); //Get the final UIImage result