[Mapserver-users] Raster geotiff turns background yellow (now turns vectors gray)

[randy james]

Hi

I did stumbled on a workaround fix for my problem;

I included line;

TRANSPARENCY 100

in my map file in the orthophotos layer. I'm not sure
why this makes a differance but it does.

Cheers
Randy

--- Steve Lime <steve.lime at dnr.state.mn.us> wrote:
> Are you using 24-bit output? The reason vector
> layers would turn grey is
> that (with 8-bit output) the map's color
> palette is probably full with greyscale colors. If
> there is no room for
> another color the software tries to find
> the closest match. If everything allocated
> previously is shades of grey
> and you try to draw something in red you're
> gonna get funky output. Older versions of MapServer
> avoided this by
> pre-allocating colors used by vector
> layers prior to drawing any raster data. 
> 
> You have 2 options:
> 
>   - use a 24-bit output format
>   - condense the number of colors in your
> orthophotography
> 
> You should be able to get by with 64, 32 or 16
> levels of grey for most
> applications. The human eye has trouble with
> differentiating grey levels, more so than with
> colors. You'd need a
> common palette across images. There are other
> benefits to doing that. A big one would be greatly
> reducing file size.
> 
> Steve
> 
> Stephen Lime
> Data & Applications Manager
> 
> Minnesota DNR
> 500 Lafayette Road
> St. Paul, MN 55155
> 651-297-2937
> 
> >>> randy james <rjames57 at yahoo.com> 01/30/03
> 12:17PM >>>
> Hi
> 
> Well I've recompiled with GD-2.0.11 and the
> orthophotos still turn all the vector layers gray if
> they are loaded before the vectors.
> 
> Seems like I am the only one experiencing this
> problem
> with raster layers?
> 
> I'll attach a couple of files from the tmp dir for
> your info.
> 
> Cheers
> Randy
> 
> --- Dylan Keon <keon at nacse.org> wrote:
> > Randy, what versions of GD and GDAL are you using?
> 
> > I believe there are 
> > issues with vector layers and the use of GD <
> 2.0.11
> > with MS 3.7.  Since 
> > you're using MS 3.7 you should probably also be
> > using GD 2.0.11 and GDAL 
> > 1.1.8.
> > 
> > Yes, both tiled and single raster layers can be
> made
> > transparent.  There 
> > are also new ways to handle transparency and image
> > output in 3.7, via 
> > use of the OUTPUTFORMAT object.  Take a look at 
> >
>
http://mapserver.gis.umn.edu/cgi-bin/wiki.pl?MigrationGuide
> 
> > for more info.
> > 
> > 
> > 
> > randy james wrote:
> > > Hi
> > > 
> > > To answer my own question: Rasters can be made
> > > transparent using the TRANSPARENCY (0-100) tag.
> > > 
> > > I have tried with a raster layer loaded through
> > > tileindex, but not with loading a raster the
> > normal
> > > way yet.
> > > 
> > > But i would hope that at some point i will be
> able
> > to
> > > load the orthophotos under the vectors without
> > been
> > > transparent, rather than on top of the vectors
> and
> > > transparent.
> > > 
> > > 
> > > --- randy james <rjames57 at yahoo.com> wrote:
> > > 
> > >>Hi
> > >>
> > >>Upgrading to 3.7 solved the problem of the tiff
> > >>image
> > >>turning the background yellow, but caused
> another
> > >>problem:
> > >>
> > >>Any vector layer that is loaded on top if the
> tiff
> > >>image now turns gray. When i load the vectors
> > after
> > >>the tiff nothing changes color at least, but i
> > >>cannot
> > >>see the vector layers.
> > >>
> > >>Can Raster layers be transparent?
> > >>
> > >>Cheers 
> > >>Randy
> > >>
> > >>
> > >>--- Frank Warmerdam <warmerdam at pobox.com> wrote:
> > >>
> > >>>randy james wrote:
> > >>>
> > >>>>Hi
> > >>>>--- Ed McNierney <ed at topozone.com> wrote:
> > >>>>
> > >>>>
> > >>>>>Randy -
> > >>>>>
> > >>>>>Can you describe exactly what you did
> > >>>>
> > >>differently
> > >>
> > >>>>>between those two images?
> > >>>>>
> > >>>>
> > >>>>Well the difference is: 
> > >>>>the tif that does not work has: a 256 RGB,
> > >>>>colorinterp=palette, is projected on the fly,
> > >>>
> > >>and
> > >>
> > >>>is a
> > >>>
> > >>>>newer version of an orthophoto.
> > >>>>I have used tiff2bw and gdal_translate to make
> > >>>
> > >>it
> > >>
> > >>>>grayscale, so i have a few versions of the
> file
> > >>>
> > >>>(5),
> > >>>
> > >>>>and all make the same error.
> > >>>
> > >>>Randy,
> > >>>
> > >>>I haven't been following this issue closely,
> but
> > >>
> > >>if
> > >>
> > >>>the problem occurs in
> > >>>3.7 and if you can prepare a small test case
> that
> > >>>demonstrates the problem
> > >>>just using "shp2img" then please file it in
> > >>
> > >>bugzilla
> > >>
> > >>>(attaching the small
> > >>>sample map file and data file(s)) and assign to
> > >>
> > >>me.
> > >>
> > >>>Best regards,
> > >>>
> > >>>-- 
> > >>>
> > >>
> > >
> >
>
---------------------------------------+--------------------------------------
> > > 
> > >>>I set the clouds in motion - turn up   | Frank
> > >>>Warmerdam, warmerdam at pobox.com 
> > >>>light and sound - activate the windows |
> > >>>http://pobox.com/~warmerdam 
> > >>>and watch the world go round - Rush    |
> > >>
> > >>Geospatial
> > >>
> > >>>Programmer for Rent
> 
=== message truncated ===


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