(let w (* 640 2))
(let h (* 480 2))
(let frame  (shader     "render"  w h))
(let avg    (shader-rec "avg"     w h frame))
(let scaled (shader     "scale"   w h avg))
(let edges  (shader     "sobel"   w h scaled))
(let crisp scaled)
(repeat 100
    (let crisp  (shader "denoise" w h edges crisp)))
(output crisp)