Andre Majorel on wrote...
| On 2007-12-24 13:01 +1000, Anthony Thyssen wrote:
| > Andre Majorel on wrote...
| > | On 2007-12-23 22:42 +1000, Anthony Thyssen wrote:
| > | > Andre Majorel on wrote...
| > | > |
| > | > | The document lends itself to quantisation very well ; it is
| > | > | typeset text with some orange highlighter so the scan contains
| > | > | only black, white and shades of fluorescent orange and grey. It
| > | > | could be adequately rendered with just, say, 8 colours : black,
| > | > | white, 3 greys and 3 shades of orange.
| > | > |
| > | > | Unfortunately, convert's native quantisation does not work that
| > | > | well with it. I end up with either too many shades of light grey
| > | > | for good compression or light brown instead of orange.
| > | >
| > | > I would specify the colors you want in a small image with just thou=
| se
| > | > colors, than use -map. That is avoid the color quantization entir=
| ely.
| > |=20
| > | Thanks but that doesn't work too well. The original image is noisy
| > | and it's not obvious how to choose shades that are distant enough
| > | to avoid the dithering but not so distant that pixels end up
| > | remapped to the wrong hue.
| > |=20
| > | And the scaling problem is still there.
| > |=20
| > You can just turn off dithering using +dither.
| > In that case -map will just set colors to the closest color found in
| > the given color map image.
|
| This *is* with +dither. It's not FS dithering, it's dithering
| resulting from noise in the output image.
|
Oh I see. That could be a problem.
Can you crop a small area from the image, containing the various parts
and send me link.
Anthony Thyssen ( System Programmer ) <[EMAIL PROTECTED]>
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