chickadee » leptonic » pix-scale-general

pix-scale-generalprocedure
  • in - PPIX
  • in - SCALEX/Y, SHARPFRAC: flaot.
  • in - SHARPWIDTH: int, 1 or 2.
  • returns: modified ppix.
    • When max scalex/y is < 0.2, no sharpening applied.
    • Between .2 and 1.4, sharpen according to input values.
    • With scalex/y > 1.4, no sharpening is applied.
    • For precise control, call (pix-scale-general ...) with sharpfrac 0.0 followed by call to (pix-unsharp-mask ...).
(import leptonic)
(include "leptonic-types.scm") 
(define-external ppix0 ppix (pix-read "img0.webp"))
(define scaledpix (pix-scale-general ppix0 1.2 1.2 0.25 1))
...
(define res (pix-write scaledpix "img0-1.2x.webp" scaledpix 15))
;; res -> 0