How to deal with image resizing for different orientations

Question

I've been following this excellent resource here: http://stackoverflow.com/questions/1282830/uiimagepickercontroller-uiimage-memory-and-more

and based some of my code off it. But can't seem to get my head around how to accomplish what I want to do.

Basically, I want to take any image from the iPhone (landscape or portrait) and display it at screen resolution (480 x 320). At the moment, I'm scaling images to the width (320) which is working almost fine with portrait images (I'm getting a bit of stretching because of the difference in aspect ratio to the 1600 x 1200 image the camera takes). Also, with the landscape images, these are far too short - they don't fill they screen.

Is there a way I can crop and scale a 320 x 480 section from a landscape image - from the middle of the image.

Here is how I'm calling my method

image = [ImageManipulator imageWithImage:image scaledToSize:CGSizeMake(480,320)];

And below is my method:

+ (UIImage*)imageWithImage:(UIImage*)sourceImage scaledToSize:(CGSize)targetSize { 
NSLog(@"Scaling image");
CGFloat targetWidth = targetSize.width; 
CGFloat targetHeight = targetSize.height;

if (targetWidth <=sourceImage.size.width && targetHeight <= sourceImage.size.height)
{
    CGImageRef imageRef = [sourceImage CGImage];
    CGBitmapInfo bitmapInfo = CGImageGetBitmapInfo(imageRef);
    CGColorSpaceRef colorSpaceInfo = CGImageGetColorSpace(imageRef);

    if (bitmapInfo == kCGImageAlphaNone) {
        bitmapInfo = kCGImageAlphaNoneSkipLast;
    }

    CGContextRef bitmap;

if (sourceImage.imageOrientation == UIImageOrientationUp || sourceImage.imageOrientation == UIImageOrientationDown) {
bitmap = CGBitmapContextCreate(NULL, targetWidth, targetHeight, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);

} else {
bitmap = CGBitmapContextCreate(NULL, targetHeight, targetWidth, CGImageGetBitsPerComponent(imageRef), CGImageGetBytesPerRow(imageRef), colorSpaceInfo, bitmapInfo);

}       

if (sourceImage.imageOrientation == UIImageOrientationLeft) {
CGContextRotateCTM (bitmap, radians(90));
CGContextTranslateCTM (bitmap, 0, -targetHeight);

} else if (sourceImage.imageOrientation == UIImageOrientationRight) {
CGContextRotateCTM (bitmap, radians(-90));
CGContextTranslateCTM (bitmap, -targetWidth, 0);

} else if (sourceImage.imageOrientation == UIImageOrientationUp) {
// NOTHING
} else if (sourceImage.imageOrientation == UIImageOrientationDown) {
CGContextTranslateCTM (bitmap, targetWidth, targetHeight);
CGContextRotateCTM (bitmap, radians(-180.));
}

CGContextDrawImage(bitmap, CGRectMake(0, 0, targetWidth, targetHeight), imageRef);
CGImageRef ref = CGBitmapContextCreateImage(bitmap);
UIImage* newImage = [UIImage imageWithCGImage:ref];

CGContextRelease(bitmap);
CGImageRelease(ref);
    return newImage;
}
else {
    NSLog(@"Finished scaling image");
    return sourceImage;
}

NSLog(@"Finished scaling image"); 
return sourceImage;
}