把长方形的图片截取成正方形

 

- (UIImage *)imageFromImage:(UIImage *)image {

    CGSize size = image.size;

    CGRect rect = CGRectZero;

    rect.size = size;

    rect.origin.x = (size.width - size.height) / 2;

    rect.size.width -= 2 * rect.origin.x;

    CGImageRef sourceImageRef = [image CGImage];

    CGImageRef newImageRef = CGImageCreateWithImageInRect(sourceImageRef, rect);

    UIImage *newImage = [UIImage imageWithCGImage:newImageRef];

    return newImage;

}