IPhone : Scale image in a memory efficient way?

Greetings-
I am trying to find the most efficient way to scale down an image captured with the camera and UIImagePickerController. As far as I can see with Allocations Instrument, any way I scale it down seems to shoot the memory footprint up 20mb (the uncompressed byte size of the iPhone 4 camera image in RGBA). That is the case even when (for an experiment) I tried scaling down to a 5x5 pixel destination image. This seems to indicate that the source image is being copied in order to scale down.
Here are the two methods I've tried so far, both causing a spike:
UIGraphicsBeginImageContextWithOptions(CGSizeMake(5,5), YES, 1.0);
[pickedImage drawInRect:CGRectMake(0.0, 0.0, 5,5)];
newImage= UIGraphicsGetImageFromCurrentImageContext();
[newImage retain];
UIGraphicsEndImageContext();
UIGraphicsBeginImageContextWithOptions(CGSizeMake(w*0.1929, h*0.1929), YES, 1.0);
CGContextRef c = UIGraphicsGetCurrentContext();
CGContextClearRect(c, CGRectMake(0,0,w*0.1929, h*0.1929));
CGContextDrawImage(c, CGRectMake(0,0,w*0.1929, h*0.1929), [pickedImage CGImage]);
newImage = [(UIImage*)UIGraphicsGetImageFromCurrentImageContext() retain];
UIGraphicsEndImageContext();
If I comment out the scaling, the memory peaks around 12mb, so I don't think its just a symptom of using the image in the image picker delegate... Is there a way to scale down an image without this drastic memory spike?
Thanks in advance
null

OK, to simplify the question-
Can anyone verify if the 20mb spike I'm seeing after pressing "Use" is somehow the captured image moving from some reserved camera memory into the segment of memory watched by Allocations instrument? Or is my thumbnail scaling actually creating a copy of the original image behind-the-scenes? When I comment out the scaling operation and simply save the original image, I don't see the spike - that's whats confusing me.

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