How to crop a UIImageView to a new UIImage in 'aspect fit' mode?

Question

I would like to create a new UIImage by cropping the image inside a UIImageVie

Answer 1

I know the answer has been but I had some problems getting above right so, I wont to post my solution too.

The problem is the image is scaled with a aspect fit, but we know the scale factor for both the width and the height. Then we can calculate the right cropping rectangle pretty easy:

-(UIImage*)crop:(CGRect)frame
{
    // Find the scalefactors  UIImageView's widht and height / UIImage width and height
    CGFloat widthScale = self.bounds.size.width / self.image.size.width;
    CGFloat heightScale = self.bounds.size.height / self.image.size.height;

    // Calculate the right crop rectangle 
    frame.origin.x = frame.origin.x * (1 / widthScale);
    frame.origin.y = frame.origin.y * (1 / heightScale);
    frame.size.width = frame.size.width * (1 / widthScale);
    frame.size.height = frame.size.height * (1 / heightScale);

    // Create a new UIImage
    CGImageRef imageRef = CGImageCreateWithImageInRect(self.image.CGImage, frame);
    UIImage *croppedImage = [UIImage imageWithCGImage:imageRef];
    CGImageRelease(imageRef);

    return croppedImage;
}