Question

I make a picture with phone (640*480) and put it inside uiimageview (300*300) with scale to fill options set.
I need to send the same image that is displayed inside uiimageview (300*300, croped, resized) to server….

How can i get it?

Answer 1

There is a quick a dirty way to do this, by rendering the UIImageView layer to a graphics context.

UIGraphicsBeginImageContext(self.bounds.size);
[self.imageView.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *resultingImage = UIGraphicsGetImageFromCurrentImageContext();
UIGraphicsEndImageContext();

you will need to import <QuartzCore/QuartzCore.h> for this.

The other way would be to do the calculations for AspectFill your self.

 CGSize finalImageSize = CGSizeMake(300,300);
 CGImageRef sourceImageRef = yourImage.CGImage;

CGFloat horizontalRatio = finalImageSize.width / CGImageGetWidth(sourceImageRef);
CGFloat verticalRatio = finalImageSize.height / CGImageGetHeight(sourceImageRef);
CGFloat ratio = MAX(horizontalRatio, verticalRatio); //AspectFill
CGSize aspectFillSize = CGSizeMake(CGImageGetWidth(sourceImageRef) * ratio, CGImageGetHeight(sourceImageRef) * ratio);


CGContextRef context = CGBitmapContextCreate(NULL,
                                             finalImageSize.width,
                                             finalImageSize.height,
                                             CGImageGetBitsPerComponent(sourceImageRef),
                                             0,
                                             CGImageGetColorSpace(sourceImageRef),
                                             CGImageGetBitmapInfo(sourceImageRef));

//Draw our image centered vertically and horizontally in our context.
CGContextDrawImage(context, 
                   CGRectMake((finalImageSize.width-aspectFillSize.width)/2,
                              (finalImageSize.height-aspectFillSize.height)/2,
                              aspectFillSize.width,
                              aspectFillSize.height),
                   sourceImageRef);

//Start cleaning up..
CGImageRelease(sourceImageRef);

CGImageRef finalImageRef = CGBitmapContextCreateImage(context);
UIImage *finalImage = [UIImage imageWithCGImage:finalImageRef];

CGContextRelease(context);
CGImageRelease(finalImageRef);
return finalImage;