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

Dylan Beaudette debeaudette at ucdavis.edu
Fri Jan 10 11:30:54 PST 2025


Hi Rich,

Now that is a good question! Perhaps an implied use of those overviews has
changed across versions, or a previously-default mapfile parameter has
changed. We didn't see anything in the changelog, but to be honest, a lot
has changed between versions and maybe I missed something.\

Here is a direct link to the file, in case that is helpful:
https://soilmap4-1.lawr.ucdavis.edu/taxa-grid-tms/taxsubgrp/typic_xerofluvents.tif

Here is a snippet from the mapfile, the same on both machines. Note that we
are using a combination of pattern matching and expressions to select files
and apply a color styling. Perhaps there was an implied change to
"processing" or "use of overviews" directives in the more recent mapserver
version?

MAP
        OUTPUTFORMAT
                NAME "png"
                IMAGEMODE RGBA
                DRIVER "AGG/PNG"
                MIMETYPE "image/png"
                EXTENSION "png"
                FORMATOPTION "GAMMA=0.75"
        END

        STATUS ON

        # set the output projection of map images to 'spherical mercator'
used by leaflet maps
        PROJECTION
                "init=epsg:3857"
        END

        ##### blue 9 from dylan
        LAYER
                NAME blue9dylan
                STATUS ON
                DATA "%type%/%name%.tif"
                TYPE RASTER
                # set the input projection of the source data
                PROJECTION
                        "init=epsg:3857"
                END
                VALIDATION
                        "type"
"^taxorder|taxsuborder|taxgrtgroup|taxsubgrp|fm\/gg|fm\/sg$"
                        "name" "^[a-zA-z_\-]+$"
                        "minvalue" "^[0-9]{1,3}$"
                END
                CLASS # NoData Values
                        EXPRESSION ([pixel] = 0)
                        STYLE
                                COLOR "#00000000"
                        END
                END
                CLASS
                        EXPRESSION ([pixel] >= %minvalue% AND [pixel] <= 2)
                        STYLE
                                COLOR "#E0F7E1"
                        END
                END
[...]

Thanks,
Dylan


On Fri, Jan 10, 2025 at 11:10 AM Richard Greenwood <
richard.greenwood at gmail.com> wrote:

> Hi Dylan,
>
> Welcome back. Why do you think the issue is related to the use of
> overviews and not something else?
>
> Rich
>
> On Fri, Jan 10, 2025 at 10:50 AM Dylan Beaudette via MapServer-users <
> mapserver-users at lists.osgeo.org> wrote:
>
>> Thanks Scott,
>>
>> I tried that: md5sums on the GeoTiffs and diff on the .map files confirms
>> that they are identical.
>>
>> The only difference between these two systems is the version of Mapserver.
>>
>> MapServer version 7.2.2 OUTPUT=PNG OUTPUT=JPEG OUTPUT=KML SUPPORTS=PROJ
>> SUPPORTS=AGG SUPPORTS=FREETYPE SUPPORTS=CAIRO SUPPORTS=SVG_SYMBOLS
>> SUPPORTS=RSVG SUPPORTS=ICONV SUPPORTS=FRIBIDI SUPPORTS=WMS_SERVER
>> SUPPORTS=WMS_CLIENT SUPPORTS=WFS_SERVER SUPPORTS=WFS_CLIENT
>> SUPPORTS=WCS_SERVER SUPPORTS=SOS_SERVER SUPPORTS=FASTCGI SUPPORTS=THREADS
>> SUPPORTS=GEOS SUPPORTS=PBF INPUT=JPEG INPUT=POSTGIS INPUT=OGR INPUT=GDAL
>> INPUT=SHAPEFILE
>>
>> MapServer version 7.6.4 OUTPUT=PNG OUTPUT=JPEG OUTPUT=KML SUPPORTS=PROJ
>> SUPPORTS=AGG SUPPORTS=FREETYPE SUPPORTS=CAIRO SUPPORTS=SVG_SYMBOLS
>> SUPPORTS=RSVG SUPPORTS=ICONV SUPPORTS=FRIBIDI SUPPORTS=WMS_SERVER
>> SUPPORTS=WMS_CLIENT SUPPORTS=WFS_SERVER SUPPORTS=WFS_CLIENT
>> SUPPORTS=WCS_SERVER SUPPORTS=SOS_SERVER SUPPORTS=FASTCGI SUPPORTS=THREADS
>> SUPPORTS=GEOS SUPPORTS=POINT_Z_M SUPPORTS=PBF INPUT=JPEG INPUT=POSTGIS
>> INPUT=OGR INPUT=GDAL INPUT=SHAPEFILE
>>
>> The newer version is provided via apt:
>> cgi-mapserver                          7.6.4-2build2
>>       amd64        CGI executable for MapServer
>>
>> Any other leads?
>> Thanks!
>> Dylan
>>
>> On Thu, Jan 9, 2025 at 2:45 PM Scott via MapServer-users <
>> mapserver-users at lists.osgeo.org> wrote:
>>
>>> 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
>>> >
>>> >
>>> >
>>> >
>>> > _______________________________________________
>>> > MapServer-users mailing list
>>> > MapServer-users at lists.osgeo.org
>>> > https://lists.osgeo.org/mailman/listinfo/mapserver-users
>>>
>>> _______________________________________________
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>>>
>> _______________________________________________
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>
>
> --
> Richard W. Greenwood
> www.greenwoodmap.com
>
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