Investigate WMS for region based csv support

[kgrochow]

No description provided.

[kgrochow]

I created a raster of the post codes and have hooked up a request tile extension to the WMSTileImageryProvider to color the image based on the pixel ID. So far the performance is good and it scales well.
Getting GeoServer to properly return the id is proving a bit tricky. I'll probably need to add some extensions to our geoserver installation. It's a lot like returning terrain from GeoServer, which is a bit fiddley.
Next I'm going to look at how this can be integrated with the table/csv data source.

[kgrochow]

Getting this to work in leaflet will be another matter since it requires fiddling with the tiles.

[kgrochow]

Kevin, I'm trying to find the best way to return an id in the color value of a pixel. Anything from 0-255 is relatively simple and beyond that looks rather custom (return bil, etc). This is very close to the WMS GeoServer Terrain problem. Did you ever spend any time with that?

[kring]

I did spend some time with that, and had a lot of trouble. Geoserver (at least at the time) was very much oriented around 8 bits per channel. So even if the source data (coming from a TIF in my case) had more precision, but the time an output plugin saw it, it had already been downsampled. The BIL plugin had a hacky way around that.

That's why our approach was to write a simple proxy that accepted a full-precision TIF file and converted it to an RGB-encoded PNG on the fly.

But to be fair, I was doing this last minute for some demo and didn't have the time to really figure it out. There could be a better solution I missed.

[kgrochow]

I did see this in the issues chain which points toward a pre-build the tile tree solution. We can talk more when we meet today.

[kring]

Sounds good. I'm struggling to remember all the details (it was almost exactly two years ago that I was working on this), but I'll tell you what I know.

[kgrochow]

I'm closing this one since the investigation part is over and the implementation part moves to issue #237.