Viewing bitmap without interpolation (with Feh or otherwise)

My preferred image viewer is Feh. When I open a small image with Feh, there is very intrusive interpolation between pixels. I would like to turn this off and just view the raw pixels. How can I do this with Feh? Or will another program be in order? Edit: I realise the original post was ambiguous. My question is better stated as "how can I view the image zoomed in with an interpolation which preserves the original blockiness?"; e.g., zooming x and y by 2 should render a single blue pixel as a 4-pixel large blue block. This intention was inferred from my OP and I have accepted an answer :)