[MapProxy] limit requests to backend by resolution

[Trond Michelsen]

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?

-- 
Trond Michelsen