[Mapserver-users] I have some landsat 7 data that I want to tile : overlap + transparency
J. Delfos
delfos18 at yahoo.com
Mon Feb 2 21:04:19 EST 2004
Stephen,
Are you trying to actually produce a printout at a resolution of 300dpi?
Because as far as I know you can't do that from a browser. A browser will
most frequently print at 96dpi. In my site, I implemented some javascript
that will zoom to a certain printing scale, for a certain pagesize. But to
do this, I have to create a map at a different size, and adjust my
extents. The printing resolution stays the same however (96dpi), it's only
the size of the print you can change. The image will not come out any
sharper from a browser. Only if you were to export your map image to an
external graphic package you might be able to get to a certain resolution.
Ed, I agree completely about the misconcept of dpi's for airial imagery.
The only way to get your imagery at a certain scale, or at a certain
resolution, is to calculate the size of a pixel, and then to either adjust
your mapsize to get a different resolution, or to adjust your map extent
to get a different scale (keeping the resolution the same).
Jacob
--- Ed McNierney <ed at topozone.com> wrote:
> Stephen -
>
> Can you explain what results you ARE getting, and what input parameters
> you're using? You've said you have "no luck", but we don't know what
> that means.
>
> Do you know what spatial resolution per pixel you are or should be
> using? That is an important part of the picture.
>
> ANY image you request that is 1,800 pixels across will be 300 DPI at 6
> inches width. WIDTH=1800 is all you need.
>
> - Ed
>
> Ed McNierney
> President and Chief Mapmaker
> TopoZone.com
> -----Original Message-----
> From: Stephen Clark [mailto:stephen.clark at focus.ca]
> Sent: Monday, February 02, 2004 3:30 PM
> To: Stephen Clark; Ed McNierney; Kralidis,Tom [Burlington]; Frank
> Warmerdam
> Cc: mapserver-users at lists.gis.umn.edu
> Subject: Re: [Mapserver-users] I have some landsat 7 data that I want to
> tile : overlap + transparency
>
> Ed or others,
>
> If you have the time could you look at the LAYER below and help me out
> with the appropriate parameters to get a 300 dpi image at 6 inches using
> the BBOX, WIDTH and HEIGHT centering on UTM Zone 10 coordinates 583695,
> 6267684.
>
> Has there been some discussions on this in the Archives because I have
> come up with a blank on this..?
>
> thanks
> Stephen
>
>
>
>
> ----- Original Message -----
> From: "Stephen Clark" <stephen.clark at focus.ca>
> To: "Ed McNierney" <ed at topozone.com>; "Kralidis,Tom [Burlington]"
> <Tom.Kralidis at ec.gc.ca>; "Frank Warmerdam" <warmerdam at pobox.com>
> Cc: <mapserver-users at lists.gis.umn.edu>
> Sent: Monday, February 02, 2004 9:14 AM
> Subject: Re: [Mapserver-users] I have some landsat 7 data that I want to
> tile : overlap + transparency
>
>
> > Ed,
> >
> > How would I do that with the following layer for CanImage:
> >
> > e.g., using the BBOX parameter ???
> >
> >
> > LAYER # Centre d'information Topographique - CIT Sherbrooke
> > NAME "CANIMAGE"
> > TYPE RASTER
> > OFFSITE 0 0 0
> > STATUS on
> > CONNECTIONTYPE WMS
> > CONNECTION "http://wms.cits.rncan.gc.ca/cgi-bin/cubeserv.cgi?"
> > METADATA
> > "wms_title" "CANIMAGE"
> > "wms_name" "CANIMAGE:CanImage/CanImage"
> > "wms_server_version" "1.1.0"
> > "wms_srs" "epsg:26910"
> > "wms_format" "image/png"
> > END
> > PROJECTION
> > "init=epsg:26910"
> > END
> > END #
> >
> >
> >
> > Thanks
> > Stephen
> >
> >
> >
> > ----- Original Message -----
> > From: "Ed McNierney" <ed at topozone.com>
> > To: "Kralidis,Tom [Burlington]" <Tom.Kralidis at ec.gc.ca>; "Stephen
> Clark"
> > <stephen.clark at focus.ca>; "Frank Warmerdam" <warmerdam at pobox.com>
> > Cc: <mapserver-users at lists.gis.umn.edu>
> > Sent: Friday, January 30, 2004 6:51 PM
> > Subject: RE: [Mapserver-users] I have some landsat 7 data that I want
> to
> > tile : overlap + transparency
> >
> >
> > Folks -
> >
> > The concept of a 300 dpi image from spatial imagery is nothing more
> than
> > a convenient fiction. EVERY WMS command produces a 300 dpi image - at
> a
> > certain output scale.
> >
> > You need to define one more variable - the geographic dimensions of a
> > pixel. This will let you calculate the image size you want. Say, for
> > example, you want to create a 300 dpi image in which each pixel
> > represents 15 meters (in each dimension). This means each inch on the
> > output product will be 300 x 15 meters, so your output scale is 1 inch
> =
> > 300 x 15 meters or 1 inch = 300 x 15 x 39.37 inches - a scale of
> > 1:177,165.
> >
> > If you'd like to do that, and produce a 6" x 6" 300 dpi image at a
> > resolution of 15 meters per pixel, your WMS request asks for 6 x 300 x
> > 15 or 27,000 meters in each dimension (in the BBOX parameter) and asks
> > for a WIDTH and HEIGHT of 1,800 pixels (6 inches at 300 dpi).
> >
> > If you'd like the image to be 10 meters per pixel, or 30 meters per
> > pixel, you would request a BBOX where delta X and delta Y were both
> > 18,000 meters or 54,000 meters respectively.
> >
> > - Ed
> >
> > Ed McNierney
> > President and Chief Mapmaker
> > TopoZone.com
> > -----Original Message-----
> > From: Kralidis,Tom [Burlington] [mailto:Tom.Kralidis at ec.gc.ca]
> > Sent: Friday, January 30, 2004 7:58 PM
> > To: 'Stephen Clark'; Frank Warmerdam
> > Cc: mapserver-users at lists.gis.umn.edu
> > Subject: RE: [Mapserver-users] I have some landsat 7 data that I want
> to
> > tile : overlap + transparency
> >
> >
> >
> > > -----Original Message-----
> > > From: Stephen Clark [mailto:stephen.clark at focus.ca]
> > > Sent: Friday, January 30, 2004 7:57 PM
> > > To: Kralidis,Tom [Burlington]; Frank Warmerdam
> > > Cc: mapserver-users at lists.gis.umn.edu
> > > Subject: Re: [Mapserver-users] I have some landsat 7 data that I
> want
> > > to tile : overlap + transparency
> > >
> > >
> > > Tom,
> > >
> > > Is this the same as the CANIMAGE WMS layer from :
> > >
> > > "http://wms.cits.rncan.gc.ca/cgi-bin/cubeserv.cgi?"
> > >
> >
> > The CanImage layer is a processed set, with no overlaps, at 15m
> > resolution.
> > The CCRS Landsat are band 743, as distributed by GeoGratis. Same base
> > product, different pre-processing done to the data. IMHO, the
> CanImage
> > product looks more seamless.
> >
> > > If so I already have this layer added to MapServer.
> > >
> > > My use of Landsat 7 Imagery is for a backdrop in my PDF files. But
> I
> > > cannot get the WMS server to produce a 300 dpi image so I need to
> copy
> >
> > > them locally to produce the 300 dpi PDF files.
> > >
> > > Do you know of a WMS command that will produce an image ad a
> > > particular DPI?
> > >
> >
> > No, anyone else got an idea here?
> >
> > ..Tom
> >
> > > thanks
> > > Stephen
> > >
> > > ----- Original Message -----
> > > From: "Kralidis,Tom [Burlington]" <Tom.Kralidis at ec.gc.ca>
> > > To: "'Stephen Clark'" <stephen.clark at focus.ca>; "Frank Warmerdam"
> > > <warmerdam at pobox.com>
> > > Cc: <mapserver-users at lists.gis.umn.edu>
> > > Sent: Friday, January 30, 2004 2:59 PM
> > > Subject: RE: [Mapserver-users] I have some landsat 7 data that I
> want
> > > to tile : overlap + transparency
> > >
> > >
> > > >
> > > > Hi Stephen,
> > > >
> > > > What are your requirements for using the Landsat 7 Orthoimagery in
> > > > MapServer?
> > > >
> > > > The CCRS WMS has the entire Landsat 7 Orthorectified Imagery
> > > > collection, which is on GeoGratis, available as OGC:WMS:
> > > >
> > > > URL:
> http://ceoware2.ccrs.nrcan.gc.ca/cubewerx/cubeserv/cubeserv.cgi
> > > > Layer name: L7O_B743:CEOWARE2
> > > >
> > > > Note that this layer is also timestamped, i.e. you can
> > > query via TIME
> > > > in OGC:WMS also. The scenes' black areas are transparent.
> > > >
> > > > Just thought it'd be easier to point to an OGC:WMS of this
> > > data rather
> > > than
> > > > roll your own.
> > > >
> > > > Another comment: I'd be interested, as a separate exercise, how
> > > > MapServer deals with overlapping images in a given layer.
> > > What kind
> > > > of algorithm is done between scenes which overlap?
> > > >
> > > > Thanks
> > > >
> > > > ..Tom
> > > >
> > > > =========================
> > > > Tom Kralidis
> > > > Systems Scientist
> > > > Environment Canada
> > > > Tel: +01-905-336-4409
> > > > http://www.ec.gc.ca/cise/
> > > >
> > > > =========================
> > > >
> > > > > -----Original Message-----
> > > > > From: Stephen Clark [mailto:stephen.clark at focus.ca]
> > > > > Sent: Friday, January 30, 2004 6:52 PM
> > > > > To: Frank Warmerdam
> > > > > Cc: mapserver-users at lists.gis.umn.edu
> > > > > Subject: Re: [Mapserver-users] I have some landsat 7 data that I
> > > > > want to tile : overlap + transparency
> > > > >
> > > > >
> > > > > Frank,
> > > > >
> > > > > My landsat data is from the Geogratis web site :
> > > > >
> > > > >
> http://geogratis.cgdi.gc.ca/download/landsat_7/ortho/geotiff/utm/
> > > > >
> > > > > Specifically these three scenes as example:
> > > > >
> > > > > http://geogratis.cgdi.gc.ca/download/landsat_7/ortho/geotiff/u
> > > > > tm/047021/
> > > > > http://geogratis.cgdi.gc.ca/download/landsat_7/ortho/geotiff/u
> > > > > tm/048021/
> > > > > http://geogratis.cgdi.gc.ca/download/landsat_7/ortho/geotiff/u
> > > > > tm/049021/
> > > > >
> > > > > I compressed the files to ECW and produced this layer:
> > > > >
> > > > > LAYER
> > > > > NAME landsat_048_021_rgb
> > > > > DATA
> > > > >
> > >
> "d:/datasets/imagery/landsat/ecw/048021_0100_990804_l7_743_utm10.ecw"
> > > > > TYPE RASTER
> > > > > STATUS ON
> > > > > TRANSPARENCY 60
> > > > >
> > > > > # turn off the black background in the image files
> > > > > OFFSITE 0 0 0
> > > > > END
> > > > >
> > > > >
> > > > > >Do all the images have the same background value? YES
> > > -- they do.
> > > > > There is a residual amount of black fuzziness around the scenes
> > > > > after using the above OFFSITE command.
> > > > >
> > > > > Here is a LAYER file for the tiled index of Landsat scenes:
> > > > >
> > > > > LAYER
> > > > > NAME landsat_tile
> > > > > TILEINDEX "d:/datasets/imagery/landsat/landsat_index.shp"
> > > > > TILEITEM "location"
> > > > > TYPE RASTER
> > > > > STATUS ON
> > > > > TRANSPARENCY 60
> > > > >
> > > > > # turn off the black background in the image files
> > > > > OFFSITE 0 0 0
> > > > >
> > > > > METADATA
> > > > > WMS_TITLE "Lansdat 7 Imagery "
> > > > > WMS_ABSTRACT "N/A"
> > > > > WMS_SRS "EPSG:26910"
> > > > > END
> > > > >
> > > > > END
> > > > >
> > > > > But this tiled layer does not have any transparency. How would
> I
> > > > > fix this?
> > > > >
> > > > > thanks
> > > > > Stephen
> > > > >
> > > > > ----- Original Message -----
> > > > > From: "Frank Warmerdam" <warmerdam at pobox.com>
> > > > > To: "Stephen Clark" <stephen.clark at focus.ca>
> > > > > Cc: <mapserver-users at lists.gis.umn.edu>
> > > > > Sent: Friday, January 30, 2004 2:31 PM
> > > > > Subject: Re: [Mapserver-users] I have some landsat 7 data that I
> > > > > want to tile : overlap + transparency
> > > > >
> > > > >
> > > > > > Stephen Clark wrote:
> > > > > > > Hi All,
> > > > > > >
> > > > > > >
> > > > > > > I have some landsat 7 data that I want to tile but the
> scenes
> > > > > > > overlap.
> > > > > > >
> > > > > > > Can I use some sort of command that can be added to the
> > > > > "gdaltindex"
> > > > > > > command to add a transparency value to these scenes
> > > so that the
> > > > > > > overlap areas can show through.
> > > > > >
> > > > > > Stephen,
> > > > > >
> > > > > > Do all the images have the same background value? If
> > > so, use it
> > > > > > as the offsite value for the whole layer and it will be used
> > > > > with all the
> > > > > > images. The other alternative is to store the tiles in a
> format
> > > > > > for which GDAL recognises "nodata" values, but this isn't very
> > > > > convenient
> > > > > > to arrange. There is no way to include nodata values in
> > > the raster
> > > > > > tile index.
> > > > > >
> > > > > > Best regards,
> > > > > > --
> > > > > >
> > > > >
> > > ---------------------------------------+----------------------------
> > > > > ---------------------------------------+--
> > > > > > ---------------------------------------+----
> > > > > ----
> > > > > > I set the clouds in motion - turn up | Frank Warmerdam,
> > > > > warmerdam at pobox.com
> > > > > > light and sound - activate the windows |
> > > http://pobox.com/~warmerdam
> > > > > > and watch the world go
> > > round - Rush | Geospatial
> > > > > Programmer for Rent
> > > > > >
> > > > > >
> > > > > >
> > > > >
> > > > > _______________________________________________
> > > > > Mapserver-users mailing list Mapserver-users at lists.gis.umn.edu
> > > > > http://lists.gis.umn.edu/mailman/listinfo/maps> erver-users
> > > > >
> > > >
> > >
> > _______________________________________________
> > Mapserver-users mailing list
> > Mapserver-users at lists.gis.umn.edu
> > http://lists.gis.umn.edu/mailman/listinfo/mapserver-users
> >
> >
>
>
>
> _______________________________________________
> Mapserver-users mailing list
> Mapserver-users at lists.gis.umn.edu
> http://lists.gis.umn.edu/mailman/listinfo/mapserver-users
__________________________________
Do you Yahoo!?
Yahoo! SiteBuilder - Free web site building tool. Try it!
http://webhosting.yahoo.com/ps/sb/
More information about the mapserver-users
mailing list