Cropping an UIImage

Question

I\'ve got some code that resizes an image so I can get a scaled chunk of the center of the image - I use this to take a UIImage and return a small, square repre

Answer 1

Heads up: all these answers assume a CGImage-backed image object.

image.CGImage can return nil, if the UIImage is backed by a CIImage, which would be the case if you created this image using a CIFilter.

In that case, you might have to draw the image in a new context, and return that image (slow).

UIImage* crop(UIImage *image, rect) {
    UIGraphicsBeginImageContextWithOptions(rect.size, false, [image scale]);
    [image drawAtPoint:CGPointMake(-rect.origin.x, -rect.origin.y)];
    cropped_image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return cropped_image;
}