[mapserver-users] Raster

[Ed McNierney]

Miroslav -

Store your images as TIFF files and use the OFFSITE keyword.  If you can
set no-data pixels to a unique value (not otherwise found in the image)
in your TIFF files, just add the OFFSITE keyword to the raster layer
with the TIFF file as data or indexed through a TILEINDEX file.  If the
value of your no-data pixel is 255, for example, then

	OFFSITE 255

will cause all pixels with that value to be treated as transparent.

	- Ed

Ed McNierney
Chief Mapmaker
TopoZone.com
ed at topozone.com
(978) 251-4242


-----Original Message-----
From: Miroslav Sodja [mailto:Miroslav.Sodja at gov.si]
Sent: Monday, February 04, 2002 4:25 AM
To: mapserver-users at lists.gis.umn.edu
Subject: [mapserver-users] Raster


Hi all,

I have questions about raster data. 

Layer with raster data has 38 images; images are about 4500 pixel width,
and 6000 pixel height with 2 colors. I have tile index of those images.
The problem is that every image has border with no data. And that border
goes across the data of neighbor image. The image should be transparent.
There is no problem if I have png file format with transparent
background and map file look like that

LAYER  #raster 50.000
	NAME "IME_50"
	TILEINDEX "raster/ko_50.shp"
	TILEITEM "PNG_NAME"
	TYPE raster
	STATUS ON
	MAXSCALE 60000
	CLASSITEM "[pixel]"
	CLASS
		EXPRESSION ([pixel] <1 )
		COLOR 0 0 0
	END
END

But response of IIS and MapServer in that case is very slow. 

If I have tiff file format of those images I have white space around
every image in layer but response of IIS and MapServer is fast. Map file
is the same except:

	TILEITEM "TIF_NAME"

I can't cut border with no data because images are deformed and new
world file would be difficult to calculate.

I have MapServer:

MapServer version 3.5 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP
SUPPORTS=PROJ SUPPORTS=TTF SUPPORTS=WMS_SERVER INPUT=EPPL7 INPUT=OGR
INPUT=GDAL INPUT=SHAPEFILE

and IIS 5.0 on Windows 2000.

Thanks for any suggestions.


Miro Sodja		miroslav.sodja at gov.si