图片裁剪 旋转 转换

     //裁剪




    -(UIImage *)getImageFromImage{
//大图bigImage
//定义myImageRect，截图的区域
CGFloat imgW = self.cutimg.size.width;
CGFloat imgH = self.cutimg.size.height;
CGRect myImageRect = CGRectMake(0.180 * imgH, 0.09375 * imgW,0.621 *imgH,0.8437 * imgW);
UIImage* bigImage= self.cutimg;

CGImageRef imageRef = bigImage.CGImage;
CGImageRef subImageRef = CGImageCreateWithImageInRect(imageRef, myImageRect);
CGSize size;
size.width = 57.0;
size.height = 57.0;
UIGraphicsBeginImageContext(size);
CGContextRef context = UIGraphicsGetCurrentContext();
CGContextDrawImage(context, myImageRect, subImageRef);
UIImage* smallImage = [UIImage imageWithCGImage:subImageRef];
UIGraphicsEndImageContext();
return smallImage;
}





    //裁剪图片
            UIImage *img = [self getImageFromImage];
            
            CGImageRef cgimage=img.CGImage;
            //旋转图片
            UIImage *IMG  = [UIImage imageWithCGImage:cgimage scale:1 orientation:UIImageOrientationRight];



//保存到相册
            UIImageWriteToSavedPhotosAlbum(IMG, self, nil, nil);