iphone - How do I make an exact copy of a UIImage returned from a UIImagePickerController?

Question

I have divergent needs for the image returned from the iPhone camera. My app scales the image down for upload and display and, recently, I added the ability to save the image to the Photos app.

At first I was assigning the returned value to two separate variables, but it turned out that they were sharing the same object, so I was getting two scaled-down images instead of having one at full scale.

After figuring out that you can't do UIImage *copyImage = [myImage copy];, I made a copy using imageWithCGImage, per below. Unfortunately, this doesn't work because the copy (here croppedImage) ends up rotated 90o from the original.

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{   
    // Resize, crop, and correct orientation issues
    self.originalImage = [info valueForKey:@"UIImagePickerControllerOriginalImage"];
    UIImageWriteToSavedPhotosAlbum(originalImage, nil, nil, nil);
    UIImage *smallImage = [UIImage imageWithCGImage:[originalImage CGImage]]; // UIImage doesn't conform to NSCopy

    // This method is from a category on UIImage based on this discussion:
    // http://discussions.apple.com/message.jspa?messageID=7276709
    // It doesn't rotate smallImage, though: while imageWithCGImage returns
    // a rotated CGImage, the UIImageOrientation remains at UIImageOrientationUp!
    UIImage *fixedImage = [smallImage scaleAndRotateImageFromImagePickerWithLongestSide:480];
    ...
}

Is there a way to copy the UIImagePickerControllerOriginalImage image without modifying it in the process?

Answer 1

This seems to work but you might face some memory problems depending on what you do with newImage:

CGImageRef newCgIm = CGImageCreateCopy(oldImage.CGImage);
UIImage *newImage = [UIImage imageWithCGImage:newCgIm scale:oldImage.scale orientation:oldImage.imageOrientation];