Opened 15 years ago
Last modified 14 years ago
#3042 closed defect
WMS Driver Clobbers Transparency — at Initial Version
| Reported by: | joelodom | Owned by: | warmerdam |
|---|---|---|---|
| Priority: | normal | Milestone: | 1.7.0 |
| Component: | GDAL_Raster | Version: | unspecified |
| Severity: | normal | Keywords: | WMS transparency |
| Cc: | nowakpl |
Description
The WMS driver is apparently reformatting raster data and loosing alpha information in the process. Here is a WMS service description:
<GDAL_WMS>
<Service name="WMS">
<ServerURL>http://mesonet.agron.iastate.edu/cgi-bin/wms/nexrad/n1p.cgi?TRANSPARENT=TRUE</ServerURL> <ImageFormat>image/png</ImageFormat> <Layers>nexrad-n1p</Layers>
</Service> <DataWindow>
<UpperLeftX>-102.017258</UpperLeftX> <UpperLeftY>47.974853</UpperLeftY> <LowerRightX>-93.570578</LowerRightX> <LowerRightY>42.602123</LowerRightY> <SizeX>948</SizeX> <SizeY>603</SizeY>
</DataWindow> <Timeout>45</Timeout>
</GDAL_WMS>
GDAL returns the raster as a 3 band PNG. If I put the following URL in my browser and load the PNG file with GDALOpen, I get a single band raster with a 4 byte color table.
