Tile image with polygons got vertical line at the edge

Ei Fujioka efujioka at DUKE.EDU
Tue Apr 17 13:15:43 EDT 2007


Thanks Steve,

Unfortunately, OUTLINECOLOR -1 -1 -1 doesn't work. It seems the vertical 
line gets the color of the polygon fill color, not outline color.

Yes, I have been looking into OpenLayers. It's a interesting project but 
not yet mature enough to build full-featured online mapping application 
(producing legend, changing symbol color on the fly, identify, filter by 
attributes etc.).

Anyway, I gave it a try. But the same results. See the screen shot.

http://seamap.env.duke.edu:8888/dev/cache/misc/tile_edge_lines_ol.jpg


As I said, I see the line when I directly get the image from Mapserver, 
suggesting this is a problem of Mapserver itself.

Both OpenLayers.Layer.MapServer and Google Map's GTileLayer simply grab 
images from Mapserver. In this regard, it is understandable that both 
end up with the same results.

Ei


Stephen Woodbridge wrote:
> Hello Ei,
> 
> Have you looked at ka-map or preferably openLayers? OpenLayers allows 
> you to easily merge mapserver and Google into a single application and 
> does all the heavy lifting.
> 
> Regarding your extra lines, this is might be cause by the fact that the 
> polygon is getting clipped to the extents of your tile. You might try 
> setting the OUTLINECOLOR -1 -1 -1 for the polygon layer so that it is 
> not draw. I do not think you would run into these problems with OpenLayers.
> 
> -Steve W
> 
> 
> Ei Fujioka wrote:
>> Hello experts,
>>
>> I have a weird problem that Mapserver images get one pixel wide 
>> vertical lines when they contain shapefiles that extend beyond the 
>> images (shapefiles are cut at the edge of the images).
>>
>> I'm developing a Google Maps application in which Mapserver layers are 
>> overlaid. As Google Map requests tiles of the map image, Mapserver 
>> sends them back. This usually works excellent. But when a tile has a 
>> shapefile extending beyond it, the tile got a kind of border line 
>> visible.
>>
>> Please see the screen shot. You'll see two vertical lines 256-pixel 
>> apart (which is the tile size).
>> http://seamap.env.duke.edu:8888/dev/cache/misc/tile_edge_lines.jpg
>>
>>
>> I tried PNG and GIF with the same results. This should have nothing to 
>> do with Google Maps because I still see the line when pulling the tile 
>> image directly onto the browser.
>> Polygons are added to the map with PHP/Mapscript. Transparency, fill 
>> color and outline color are set.
>>   $layer->set('transparency',"30");
>>   ...
>>   $poStyle = ms_newStyleObj($class_tmp);
>>   $poStyle->outlinecolor->setRGB(255,0,0);
>>   $poStyle->color->setRGB(200, 100, 0);
>>
>> Any workaround?
>>
>>
>> MapServer version 4.2.2 OUTPUT=GIF OUTPUT=PNG OUTPUT=JPEG OUTPUT=WBMP 
>> OUTPUT=PDF SUPPORTS=PROJ SUPPORTS=FREETYPE SUPPORTS=WMS_SERVER 
>> SUPPORTS=WMS_CLIENT SUPPORTS=WFS_SERVER SUPPORTS=WFS_CLIENT 
>> INPUT=POSTGIS INPUT=OGR INPUT=GDAL INPUT=SHAPEFILE
>>
>> Thanks,
>>
>>
>> Ei
>>
>>
> 
> 

-- 
======================
   Ei Fujioka
   Research Associate
   Duke University

   (919) 613-8021
   efujioka at duke.edu
======================



More information about the mapserver-users mailing list