Image attached. System: Mac, OS X 10.8.5, Racket 5.3.6.
Dan On Tue, Nov 19, 2013 at 11:28 AM, Robby Findler <[email protected] > wrote: > I'm not seeing what you're seeing, I think. Can you send a screenshot (or > a pointer to it)? > > Robby > > > On Mon, Nov 18, 2013 at 5:59 PM, Daniel Prager > <[email protected]>wrote: > >> Why does the following code generate visual artefacts along the right and >> bottom >> edges of the image? How do I eliminate it? >> >> #lang racket >> (require 2htdp/image) >> >> (define (crop-to-aspect-ratio im final-width final-height) >> (let* ([W (image-width im)] >> [H (image-height im)] >> [wh-ratio (/ final-width final-height)] >> [w (* wh-ratio H)] >> [h (/ W wh-ratio)] >> [image (if (<= W w) >> (crop 0 (/ (- H h) 2) W h im) >> (crop (/ (- W w) 2) 0 w H im))]) >> (freeze (scale (/ final-width (image-width image)) >> image)))) >> >> (scale 5 >> (crop-to-aspect-ratio >> (freeze (rectangle 259 356 'solid 'red)) >> 40 56)) >> >> >> Note that the two freeze instructions are essential -- the one in the >> crop routine >> forces pixelation, which I want -- and the one in the calling code >> simulates starting with a bitmap. >> >> Thanks >> >> Dan >> >> ____________________ >> Racket Users list: >> http://lists.racket-lang.org/users >> >> > -- *Daniel Prager* Agile/Lean Coaching, Software Development and Leadership Twitter: @agilejitsu <https://twitter.com/agilejitsu> Blog: agile-jitsu.blogspot.com
<<attachment: crop-and-scale-artefact.png>>
____________________ Racket Users list: http://lists.racket-lang.org/users
