The following code helps to get scaled image (UIImage) for a existing image (UIImage)

    // Create a bitmap graphics context
    // This will also set it as the current context
    // Draw the scaled image in the current context
    [self drawInRect:CGRectMake(0, 0, size.width, size.height)];
    // Create a new image from current context
    UIImage* scaledImage = UIGraphicsGetImageFromCurrentImageContext();
    // Pop the current context from the stack
    // Return our new scaled image
    return scaledImage;