Why does PI change the size of my RAW images?

[dlp]

Just been processing some 14bit RAW .NEF files from my Nikon, and I notice that PI changes the size from 4928x3264 to 4948x3280. In the processing dialogue I notice that it shows thumbnail size as 4928x3264, with the image size as 4948x3280. I think this Nikon format is fairly new (with the D7000) and Camera Raw needed an update to use them. It's really no sweat as the files turn out fine, but just wondered if this is a Nikon or PI thing?

David

[Conor]

Yeah, you might notice a little black border around the edge of your image.
This is an image processing trick for matrix operations. The edge problem
is one where your matrix filter overlaps the edge of the image where you
want to operate on edge pixels. It's pretty easy to crop this out if it really
bothers you.

Padding the image is the most efficient means of handling the edge problem
in my opinion. There are other methods, but they introduce processing overhead.
(Those bounds checks add up you know...)