negative values and colors in Ascii Grids

[Frank Warmerdam]

On 1/16/06, Carola Jesch <cjesch at cct.lsu.edu> wrote:
> Hi Frank,
> I had a look to the raster-howto and the sources as well, but was unsure,
> because I can't imagine that most users have grids that exactly have values
> between 0 and 255 in it.

Carola,

Well, most folks are working with simple 8bit images where
scaling is not required.

> So sorry fot the questions.
> Do you plan to implement a colormap for ascii grids like the clr for binary
> grids?

I wasn't planning to do so, but it looks like it wouldn't be too hard.
Note that ASCII grids are a terrible format to run mapserver from
due to the amount of processing required when reading it.

> What would you suggest to display the negative values?

If you want detailed control of the colors then create a series of
classes.  If a greyscale is fine then just use automatic or
explicit scaling values.

Best regards,
--
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
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