OC裁剪指定frame图片

image.png

引用IOS自带framework中的Accelerate

- (UIImage *)croppedImageWithFrame:(CGRect)frame {
    
    frame = CGRectMake(frame.origin.x * self.scale,
                       frame.origin.y * self.scale,
                       frame.size.width * self.scale,
                       frame.size.height * self.scale);
    
    CGImageRef sourceImageRef = [self CGImage];
    CGImageRef newImageRef    = CGImageCreateWithImageInRect(sourceImageRef, frame);
    UIImage   *newImage       = [UIImage imageWithCGImage:newImageRef scale:[self scale] orientation:[self imageOrientation]];
    CGImageRelease(newImageRef);
    return newImage;
}