iOS 开发 图片缩略图的生成，展示图片中间一部分

- (UIImage *)cutImage:(UIImage*)image1{

   if (image1.size.height>image1.size.width){

         self.image = [UIImageimageWithCGImage:CGImageCreateWithImageInRect([image1      CGImage],CGRectMake(0,fabs(image1.size.height - image1.size.width)/2.0,              image1.size.width, image1.size.width))];

        

    }else{

         self.image = [UIImageimageWithCGImage:CGImageCreateWithImageInRect([image1         CGImage],CGRectMake( fabs(image1.size.height - image1.size.width)/2.0,0,             image1.size.height, image1.size.height))];

    }

   

   return image1;

}