UIImage*img= [self imageWithImageSimple:image scaledToSize:CGSizeMake(210.0, 210.0)];//压缩图片  
      
    - (UIImage*)imageWithImageSimple:(UIImage*)image scaledToSize:(CGSize)newSize  
    {  
         // Create a graphics image context  
         UIGraphicsBeginImageContext(newSize); // Tell the old image to draw in this newcontext, with the desired  
          
         // new size  
         [image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];  
          
         // Get the new image from the context  
         UIImage* newImage = UIGraphicsGetImageFromCurrentImageContext();  
           
         // End the context  
         UIGraphicsEndImageContext();  
           
         // Return the new image.  
         return newImage;  
    }