[Tilecache] Text labels getting smudged with tilecache

[Christopher Schmidt]

On Thu, Nov 08, 2007 at 10:39:33AM -0500, Chris Holmes wrote:
> 
> 
> Christopher Schmidt wrote:
> >On Thu, Nov 08, 2007 at 06:58:28PM +0530, louvy.joseph at gmail.com wrote:
> >>Fonts are getting smudged/smeared through tilecache while the same tile 
> >>if not passed through tilecache comes out much crisper from the 
> >>geoesrver. Has anybody seen this issue? It does not happen for every 
> >>text label though. Lines or points are fine; the problem is only with 
> >>the labels. I am guessing that this is some kind of problem with PIL. 
> >>Isn't the PIL supposed to blindly cut the metaTile? Why would it change 
> >>the colors? Has anybody seen this? And what could be the root cause?
> >
> >Are you sure you're using the same mime type to talk directly to
> >GeoServer as TileCache is? I'd expect that you've probably got different
> >image configurations... for example, one is requesting png8, one is
> >requesting png24, somehow.
> >
> >Regards,
> 
> I actually haven't yet figured out how to make TileCache request png8's 
> from GeoServer.  It says that only png, jpeg and gif are available for 
> the output types.  To get png8's from GeoServer right now you have to 
> say 'png8' for the output format, or else specify a palette on 'png'. 
> But TileCache doesn't seem to allow you to specify png8.  We're working 
> on some sort of 'auto' param, but is there any way to get TileCache to 
> request png8 for the output format from the server?

TileCache uses the 'extension' property of the layer for three things:

 * 'image/'+extension as the 'format' parameter of the request.
 * filename extension in the DiskCache key
 * mime type served by the server (image/png).

This means that 'format=' requests which are not a mimetype don't work
right now, though it wouldn't be too hard for me to patch. 

Regards,
-- 
Christopher Schmidt
MetaCarta