[GRASS-dev] cause for bad colors in output from png driver

[Michael Barton]

Glynn,

I finally isolated the cause of the color issue I¹m having with the PNG
driver.

It is the GRASS_TRUECOLOR setting.

If this is set to false, then the PNG looks fine, except that it uses a
limited color pallet. If it is set to true, the PNG has black where it
should be white and other issues.


GRASS_PNG_AUTO_WRITE=TRUE
export GRASS_PNG_AUTO_WRITE
GRASS_RENDER_IMMEDIATE=TRUE
export GRASS_RENDER_IMMEDIATE
GRASS_TRUECOLOR=TRUE
export GRASS_TRUECOLOR
GRASS_PNGFILE=map.png
export GRASS_PNGFILE

GRASS 6.3.cvs (spearfish60_test):~ > d.barscale tcolor=green
PNG: GRASS_TRUECOLOR status: TRUE
PNG: collecting to file: /Users/cmbarton/map.png,
GRASS_WIDTH=640, GRASS_HEIGHT=480
WARNING: Color: can't set color -256

This gives a black background to the barscale

GRASS 6.3.cvs (spearfish60_test):~ > d.legend elevation.10m
PNG: GRASS_TRUECOLOR status: TRUE
PNG: collecting to file: /Users/cmbarton/map.png,
GRASS_WIDTH=640, GRASS_HEIGHT=480
WARNING: Color: can't set color -256
WARNING: Color: can't set color -16843264
WARNING: Color: can't set color -33686272
WARNING: Color: can't set color -50529280
WARNING: Color: can't set color -50529280
...
A lot more of these errors. This is what is locking up the wxPython overlay
routine

If I set GRASS_TRUECOLOR=FALSE, I get no errors, d.barscale is correct, but
of course the FP colors in d.legend do not display properly.

Michael
__________________________________________
Michael Barton, Professor of Anthropology
School of Human Evolution & Social Change
Center for Social Dynamics and Complexity
Arizona State University

phone: 480-965-6213
fax: 480-965-7671
www: http://www.public.asu.edu/~cmbarton 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.osgeo.org/pipermail/grass-dev/attachments/20070509/893e8757/attachment.html