iOS: How To Crop Image

ios_crop_image.m

 (UIImage *)imageFromImage:(UIImage *)image inRect:(CGRect)rect {
    CGImageRef sourceImageRef = [image CGImage];
    CGImageRef newImageRef = CGImageCreateWithImageInRect(sourceImageRef, rect);
    UIImage *newImage = [UIImage imageWithCGImage:newImageRef];
    CGImageRelease(newImageRef);
    return newImage;
}

If you have implemented that function above. You can crop images using the code below (crop the image "whoeImage.png" to a rectangle (0,0,40,40)).

UImage *img = [UIimage imageNamed:@"wholeImage.png"];   

UIImage *croppedImage   = [self imageFromImage:img inRect:CGRectMake(0, 0, 40, 40)];

Now you have a cropped UIImage named "croppedImage".