How to crop the UIImage?

Question

I develop an application in which i process the image using its pixels but in that image processing it takes a lot of time. Therefore i want to crop UIImage (Only middle par

Answer 1

Using the function

CGContextClipToRect(context, CGRectMake(0, 0, size.width, size.height));

Here's an example code, used for a different purpose but clips ok.

- (UIImage *)aspectFillToSize:(CGSize)size
{
    CGFloat imgAspect = self.size.width / self.size.height;
    CGFloat sizeAspect = size.width/size.height;

    CGSize scaledSize;

        if (sizeAspect > imgAspect) { // increase width, crop height
            scaledSize = CGSizeMake(size.width, size.width / imgAspect);
        } else { // increase height, crop width
            scaledSize = CGSizeMake(size.height * imgAspect, size.height);
        }
    UIGraphicsBeginImageContextWithOptions(size, NO, 0.0f);
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextClipToRect(context, CGRectMake(0, 0, size.width, size.height));
    [self drawInRect:CGRectMake(0.0f, 0.0f, scaledSize.width, scaledSize.height)];
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
}