[gdal-dev] WMS, blocksize and black lines

[Arno Gerretsen]

Hi all,

I'm trying to create a WMS XML to access some WMS data in GDAL. But I 
get black lines in the resulting image. I have found out that if I 
reduce the size of the BlockSize in the WMS XML that the lines get more 
narrow, but the download speed of the images also reduces a lot. Am I 
missing some setting here to make it work?

This is the XML file I use:

<GDAL_WMS>
   <Service name="WMS">
     <Version>1.1.1</Version>
     
<ServerUrl>https://gis.apfo.usda.gov/arcgis/services/NAIP/Illinois/ImageServer/WMSServer?SERVICE=WMS</ServerUrl>
     <Layers>0</Layers>
     <SRS>EPSG:4326</SRS>
     <ImageFormat>image/tiff</ImageFormat>
     <Transparent>FALSE</Transparent>
     <BBoxOrder>xyXY</BBoxOrder>
   </Service>
   <DataWindow>
     <UpperLeftX>-91.562525</UpperLeftX>
     <UpperLeftY>42.562525</UpperLeftY>
     <LowerRightX>-87.437470</LowerRightX>
     <LowerRightY>36.937474</LowerRightY>
	<SizeX>370834</SizeX>
     <SizeY>625056</SizeY>
   </DataWindow>
   <BandsCount>4</BandsCount>
   <UnsafeSSL>true</UnsafeSSL>
   <BlockSizeX>1024</BlockSizeX>
   <BlockSizeY>1024</BlockSizeY>
</GDAL_WMS>

And this is a sample call that shows the black lines:

gdal_translate -projwin -88.0 42.0 -87.99 41.99 wms.xml test.tif

With regards,

-- 
Arno