[MapProxy] limit requests to backend by resolution

[Just van den Broecke]

Hi,

This is not yet possible (if I am not wrong) as I looked for the same 
functionality: for example having an MBTiles or GeoPackage cache 
containing zoomlevels 0-12. If zoomlevel 13 is requested then in my 
preferred case MapProxy would not request an image from the (WMS) 
backend but I envision this scenario:

- take a cached tile from level 12
- scale up and "cut-out" the level 13-tile
- optionally store the level 13 tile
- etc

This is thus also very useful on installs where there is no backend WMS.
So I think we are looking for the same feature...

Best,

Just van den Broecke

On 10-10-17 18:02, Trond Michelsen wrote:
> Hi.
> 
> I have an image served through wms, which is 10980x10980 pixels in
> size. I'm wondering if it's possible to limit which resolutions
> mapproxy requests from the backend, while still return tiles?
> 
> I know I can use min_res and max_res to limit what mapproxy will
> serve, but I'd like mapproxy to scale the image itself, rather than
> refetching it from the backend.
> 
> Example:
> 
> The full size of this image, on the various zoomlevels are:
> 
> 00: 1x1
> 01: 1x1
> 02: 3x3
> 03: 5x5
> 04: 11x11
> 05: 21x21
> 06: 43x43
> 07: 86x86
> 08: 172x172
> 09: 343x343
> 10: 686x686
> 11: 1372x1372
> 12: 2745x2745
> 13: 5490x5490
> 14: 10980x10980
> 
> So, obviously, it's not very useful to serve this layer on zoomlevel
> 0-4. But, for level 5-11, I'd like mapproxy to request the full image
> from the backend at level 12, then resize it and fill the cache for
> all relevant zoom levels.
> 
> Is that possible?
>