iOS：压缩图片

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;  
}     </pre>