[MapServer-users] Varying use of overviews across Mapserver versions

[Scott]

I would do a sanity check first, just to make sure the 2 raster files 
are truly the same. Try something like:

gdalinfo -stats -hist file1.tif
gdalinfo -stats -hist file2.tif

Then, I would continue with the .map files, to make sure they are the 
same. Something like:

diff serv1.map serv2.map

See what falls out.

On 1/9/25 13:10, Dylan Beaudette via MapServer-users wrote:
> 
> Hi Everyone,
> 
> I've got identical GeoTiffs and .map files on two servers with varying 
> versions of Mapserver that is being used as a TMS. Mapserver 7.2.2 is (I 
> think) correctly using the overviews while Mapserver 7.6.4 is not.
> 
> Here is an example of the same file, tile, and styling applied across 
> both versions of Mapserver.
> 
> # Mapserver 7.2.2:
> https://soilmap2-1.lawr.ucdavis.edu/cgi-bin/mapserv?map=/data1/website/ 
> ste/ 
> taxa.map&mode=tile&tilemode=gmap&tile=5+12+5&layer=blue9dylan&type=taxsubgrp&name=typic_xerofluvents&minvalue=5 <https://soilmap2-1.lawr.ucdavis.edu/cgi-bin/mapserv?map=/data1/website/ste/taxa.map&mode=tile&tilemode=gmap&tile=5+12+5&layer=blue9dylan&type=taxsubgrp&name=typic_xerofluvents&minvalue=5>
> 
> Mapserver 7.6.4:
> https://soilmap4-1.lawr.ucdavis.edu/cgi-bin/mapserv?map=/data1/website/ 
> ste/ 
> taxa.map&mode=tile&tilemode=gmap&tile=5+12+5&layer=blue9dylan&type=taxsubgrp&name=typic_xerofluvents&minvalue=5 <https://soilmap4-1.lawr.ucdavis.edu/cgi-bin/mapserv?map=/data1/website/ste/taxa.map&mode=tile&tilemode=gmap&tile=5+12+5&layer=blue9dylan&type=taxsubgrp&name=typic_xerofluvents&minvalue=5>
> 
> It appears to me that the newer version is either ignoring or 
> interpreting the overviews differently. Each file has an internal tiling 
> and overview scheme like this:
> 
> ----------------------------------------------------------------------------------
> Band 1 Block=1766x4 Type=Byte, ColorInterp=Gray
>    NoData Value=0
>    Overviews: 883x1262, 442x631, 221x316, 111x158
> ----------------------------------------------------------------------------------
> 
> Does anyone have a clue about the differences? Is either version in error?
> 
> Thanks, and good to be back on the mailing list after a nearly 15 year 
> hiatus!
> Dylan
> 
> 
> 
> 
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