Re: Smooth Scaling from Wextech

[Sergej Rinc <sergej -dot- rinc -at- SKB -dot- SI>]

Buck & Tilly Buchanan wrote:
>
> I have been experiencing some difficulty getting screen shots not to
> look as if they had been *posterized* (a kind of number-painting look).
> This also happens on some of the scans that I import into PowerPoint.
>
> Have tried different resolutions from 96x96 to 600x600, with varying
> levels of the same problem.
>
> Anyone know of a cause and possible fix?

  Are you using 16-color (4-bit) images? Because of algorythms involved
in rescaling any (well, almost any :-) resizing program works best with
at least 256-color (8-bit) images. If you start with an 16-color image,
you probably get results as described.

  The solution? Increase number of colors to 256 with some painting
program, then use Smooth Scaling to resize the image and after that
decrease number of colors back (to reduce file size - you know why). If
that doesn't give you good results try to limit colors (if you have
images of dialog boxes) to 4 or at most 6 (e.g. black, white, gray plus
3 additional colors). In that way black fonts will remain black and
you'll keep readability after rescaling and decreasing colors back to
16-color pallete. Otherwise one of the colors may become dominant (we
had such cases when all fonts after rescaling become purple etc).

--
Sergej Rinc
Technical Director, Sinonim d.o.o.
Prekorje 49, 3211 Skofja vas
tel. +386 63 411 260 (8-15 CET: +386 61 171 5324)
fax/BBS +386 63 411 448
mailto:sinonim -at- mojster -dot- si, mailto:sergej -dot- rinc -at- skb -dot- si (file attachm.)

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