question: Does it support raster data?

[EverWinter23]

Can we store/map raster data using postgis + martin to speed up rendering on the client side?

Edit: And if it does not, how can that be achieved?

[stepankuzmin]

Hi! Currently, martin doesn't support raster tiles, but it can be added in the feature releases.

[Baschdl]

@stepankuzmin Did you already think about how one could implement this? Resorting to mapnik etc. for rendering and just serving the resulting raster tiles?

[jferencik]

@Baschdl do you have any news on this feature?

@stepankuzmin, is the mapnik solution feasable in this case?

thanks

[Baschdl]

No, I didn't pursue this idea further

[EverWinter23]

@Baschdl Maybe this helps?

Take a look at mbtiles format. Use GDAL's gdal2mbtiles to tile the GeoTiff [raster source] and then use mbtile-server to serve them to the frontend which can be consumed by mapbox, OSM etc.

[nyurik]

Update: Yes, Martin has been able to serve raster tiles from postgres, mbtiles, and pmtiles for a while now.

To try it out (if you have Rust installed, from the root of the Martin repo) - just do cargo run tests/fixtures/files/ and there is a test file that contains jpgs -- so you can get a tile from http://0.0.0.0:3000/geography-class-jpg/0/0/0

If you have an mbtiles file with images, you can just run martin myfile.mbtiles and it should work too.

[nyurik]

Once again -- this is already working.

I guess we could do some sort of a demo on how to server raster tiles, but at the end of the day, Martin does not care about the tile content, with the possible exception of how tilejson is constructed which already supports it.

To try it out (if you have Rust installed, from the root of the Martin repo) - just do cargo run tests/fixtures/files/ and there is a test file that contains jpgs -- so you can get a tile from http://0.0.0.0:3000/geography-class-jpg/0/0/0

[sharkAndshark]

Maybe we could support raster in PostGIS? Like using the ST_Tile?

[nyurik]

@sharkAndshark if someone wants to get raster from PostGIS, they can add a pg function that Martin will auto-discover, and use a SQL comment that you implemented to indicate that the tile is a jpg. (comments are to be released soon).

I am not certain there is much value in supporting the auto-discover "serve from a table" approach like we do with MVTs. If you can come up with a good approach for auto-discovery for a raster-containing tables that would be generic enough, sure, lets discuss.

[sharkAndshark]

I guess some user have no time to learn or not familiar with writing SQL function. Before we konw the correct way, some thoughts :

• Give a guide/demo about using function with raster data in PostgreSQL
• Any plan to support COG or other formats?

[nyurik]

SQL functions are trivial to write for anyone already doing SQL, i.e. they either know SQL (that's why they have a DB) -- so its not that difficult, or they don't know SQL, in which case it doesn't matter as they won't use a DB. So in short - yes, please submit PRs for improving documentation on how to do this 😄

Sure, I am all for supporting formats like COG if anyone is interested in implementing it. This is very similar to PMTiles support, and eventually we should position Martin as a web-native tile server (PRs welcome!)