Scaling a UIImage. Use in a category on UIImage.

gistfile1.txt

/* from Bill Dudney's Practical Drawing session at 2011 WWDC */
+ (UIImage *)scaleImage:(UIImage *)image toSize:(CGSize)newSize {
    UIGraphicsBeginImageContextWithOptions(newSize, YES, 0.0);
    CGRect imageRect = {{0.0, 0.0}, newSize};
    [image drawInRect:imageRect];
    UIImage *scaledImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return scaledImage;
}