Am 17.04.2012 19:54, schrieb zzzzzz:
> What should be the best way to achieve this ?
> The Dreambox expects an 8-bit paletted PNG file
Are you sure 24 bit PNG with 8 bit alpha channel doesn't cut it?
> Right now I create the image in TGA format in Povray with the +ua option, so
> that the background is transparent.
> Then I use Imagemagick to convert this image to GIF, thereby automatically
> converting the 24 bit colour with 8 bit alpha channel to a 256 colour palette
> file, then convert it with the same tool to PNG.
> The result is far from perfect, though.
Of course - GIF supports only one single transparent palette entry. As
far as I know, PNG does support semi-transparent palette entries.
> As you can see from the edges, the edges are rough because of this double
Can't you convert from TGA to 8-bit paletted PNG directly? I'd expect
Imagemagick to be able to do that stunt.
> I was wondering if there was a way to immediately create such an 8-bit paletted
> PNG file from within Povray itself, or if there is another, better way to obtain
> this result.
> Does anyone know a way of doing this ?
POV-Ray does not support paletted image output in any format; the reason
is that there are plenty of different ways of choosing a suitable
palette, and plenty of different ways to dither the image, each with
their own strength and weaknesses, so we leave that job up to image
processing software as a post-processing step.
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