iOS 图片压缩

- (UIImage *)fitImageSizeWith:(UIImage *)img{    float destWith = 600.0;    float destHeight = 600.0;        CGSize itemSize = CGSizeMake(destWith, destHeight);    UIGraphicsBeginImageContext(itemSize);    CGRect imageRect = CGRectMake(0, 0, destWith + 1, destHeight);    [img drawInRect:imageRect];    UIImage *newImg = UIGraphicsGetImageFromCurrentImageContext();    UIGraphicsEndImageContext();        return newImg;}