[mapserver-users] Return pixel values from raster layers served by mapserver

[Andrea Peri]

Hi,
I guess you could get it as a normally GetFeatureInfo request.

We use it usually to retrive the quote from a raster DEM.

You should set a template and do a request GetFeatureInfo with output
format = text/html.

In the template you should retrieve :
the RGB values separatelly for R,G and B or for a raster DEM the quote value.

AFAIK The only relevant difference difference is the input format.
Infct we use the spatialite using the OGR.
But I guess it should work also with postgis provider.

regards,

A.


2015-01-06 15:58 GMT+01:00 Bill Hudspeth <bhudspeth at edac.unm.edu>:
> Hello,
>
> I previously wrote about this issue, but have not found a solution yet. I am running Mapserver 6.4.1, and am using Postgres/Postgis to display a time series of geotiff images. I would like to know the best way for a user to submit a given x,y coordinate pair and return the pixel value for a given image. Is this possible using only the mapserver api? or must I absolutely use mapscript?
>
> Currently, I use a PostgreSQL/PostGIS time-enabled table to store the information about the location of the geotiffs and the timestamp associated with them:
>
> pm25_monthly=# \d pm25_monthly_global
>
>   Table
> "public.pm25_monthly_global"
>
>    Column  |            Type             |
> Modifiers
>
> ----------+-----------------------------+-----------------------------------------------
>
> oid | integer | default nextval('pm25_monthly_seq'::regclass)
>   rundate | timestamp with time zone |
>   datetime    | timestamp with time zone    |
>   location    | text                        |
>   timezone    | timestamp without time zone |
>   the_geom     | geometry(MultiPolygon,4326) |
>
> Indexes:
>      "pm25_monthly_global_oid_key"
> UNIQUE CONSTRAINT, btree (oid)
>
> The 'location' field simply gives the full path to the relevant geotiff on the file system. And, I define the index in the mapfile:
>
> #**********LAYER - TILE INDEX FOR PM2.5 RASTERS
> (Time sensitive)****
> LAYER
>    STATUS ON
>    NAME "pm25_time_index"
>    TYPE POLYGON
>    DATA "the_geom from pm25_monthly_global using unique oid using SRID=4326"
>    METADATA
>      "ows_title" "PM25 TIME INDEX"
>      "ows_srs" "EPSG:4326"
>      "ows_extent" "-180 -90 180 90" #[minx][miny][maxx][maxy]
>      "wms_timeformat" "YYYY-MM-DDTHH:MM:SS"
>      "wms_timeextent" "2011-01-01T00:00:00/2012-12-01T00:00:00"
>      "wms_timeitem" "timezone"
>      "wms_timedefault" "2011-01-01T00:00:00"
>      wcs_resolution '0:10 0:10'
>    END
>
>    #CONNECTION "user=wilbur dbname=pm25_monthly host=localhost password=iiiiiiiiii"
>    #CONNECTIONTYPE postgis
>    CONNECTIONTYPE POSTGIS
>    CONNECTION "host=127.0.0.1 dbname=pm25_monthly user=wilbur password=EUR2_live port=5432"
>
>    DATA "the_geom from pm25_monthly_global using unique oid using srid=4326"
> END
>
> #*******LAYER - MONTHLY PM2.5 (Time Sensitive)*********************************
>
> LAYER
>      NAME 'pm25_monthly'
>      TYPE RASTER
>      STATUS ON
>      DEBUG OFF
>      DUMP TRUE
>      #TRANSPARENCY 50
>      #FILTER ""
>
>      METADATA
>          "ows_keywordlist" 'PM2.5 (ug/m3), Global' #wms_keywordlist (Keywordlist)
>          "ows_description" "Global monthly mean PM 2.5 (ug/m3)concentration"
>          "ows_name" "Global monthly mean PM2.5 - Concentration Values (ug/m3)"
>          "ows_label" "Global PM 2.5 (ug/m3)"
>          "ows_srs" "EPSG:4326 EPSG:900913"
>          "ows_extent" "-180 -90 180 90" #[minx][miny][maxx][maxy]
>          "ows_formats" "GEOTIFF"
>          "ows_nativeformat" "8-bit GeoTIF"
>          "ows_timeitem" "timezone"
>          "wms_onlineresource" "http://localhost/cgi-bin/mapserv?map=/var/www/pm25_mapserver/public_html/pm25_ogc_services.map"
>          "wms_abstract" 'Global monthly mean PM 2.5 (ug/m3)concentration'  #wms_abstract(Abstract)
>          "wms_opaque" '0' #wms_opaque(layer)
>          "wms_title" "Global monthly mean PM 2.5 (ug/m3)concentration"
>          "ows_timeformat" "YYYY-MM-DDTHH:MM:SSZ"
>          "ows_timeextent" "2011-01-01T00:00:00Z/2012-12-01T00:00:00Z"
>          "ows_timedefault" "2011-01-01T00:00:00Z"
>          "wms_enable_request" "*"
>          "wcs_resolution" "0:10 0:10"
>          "wcs_bandcount" "1"
>          "wcs_size" "3600 1800"
>          layer_name pm25_monthly
>
>      END   #METADATA
>      PROJECTION
>          "init=epsg:4326"     #WGS84 Decimal Degrees
>      END  #PROJECTION
>
>      TILEITEM "location"
>      TILEINDEX "pm25_time_index"
>
> END  #LAYER
>
>
>
> Thanks
> _______________________________________________
> mapserver-users mailing list
> mapserver-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-users



-- 
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Andrea Peri
. . . . . . . . .
qwerty àèìòù
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