Denis Rykov

There is a [method](https://github.com/mapproxy/mapproxy/blob/53745e70b628b20c172709fd1503b67dea2b27d0/mapproxy/cache/mbtiles.py#L111) for doing that but I don't see it being called anywhere.

Could someone please review this PR?

I don't think that "application/json" should be part of the `image_formats` list. I would say that introducing something like `legend_formats` could be better way to tackle the issue.

@stijn-at-work just ask it in this thread. But even better if you would create a PR and mark it as 'draft' then we can move the discussion there.

I guess that the root cause of the issue is due to the fact the first and the second band have different masks.

In "Synthetic data written and re-read" example you can see that first band mask has 3 unmasked items whilst the second band is completely masked.

Can you please attach example of tiny `*.gpkg` to reproduce this issue?

Make tile with gdal_translate (with mask): ``` $ gdal_translate -projwin 119974.152936 2855615.99731 265006.012536 2717757.29023 \ -outsize 256 256 data.vrt tile-gdal-mask.tif ```  Make tile with gdal_translate (without mask): ``` $...

``` In [1]: import rasterio, rio_tiler, platform In [2]: rasterio.__version__ Out[2]: '1.2.6' In [3]: rio_tiler.__version__ Out[3]: '2.0.8' In [4]: rasterio.gdal_version() Out[4]: '3.3.0' In [5]: platform.system() Out[5]: 'Linux' ```

Thank you @vincentsarago for your prompt reply. Maybe I'm missing something but shouldn't these masks be the same?  https://gist.github.com/drnextgis/5a25cf2e87b380e034a72c4a150358c6