[seek-dev] RE: pgm_cut program

Arcot Rajasekar sekar at sdsc.edu
Tue Jul 13 11:20:23 PDT 2004


Hi David
	We can do this on the server side also. SRB supports what is
called a proxy operation for just this purpose.

	raja

On Tue, 13 Jul 2004, David Stockwell wrote:

> Hi,
> pgm_cut.c is a client program that just implements the srb library
> fread and fseek routines. I thought about implementing more
> functions on the server side but that is a much bigger project.
>
> There is an argument of just having a cut function on the
> server side, as a cut (or crop) must reduce the data to be
> transferred. Some other operations like rescaling may
> increse the size of the data to be transferred, and besides
> may put a lot of load on the server.
>
> GDAL seems useful, but it may make sense to modify
> it so it could be used on the client side to make simple
> SRB (or ecogrid) calls. I have been hoping for something
> like this on the server side but  I am not in a position to
> modify the SRB.
>
> Cheers
>
>
> Dave Vieglais wrote:
>
> > Hi Bing and Dave,
> > I was wondering if you had considered using tools more appropriate for
> > handling geospatial data?  The pgm libraries handle image data ok, but
> > spatial raster data sets have a number of nuances that require
> > additional processing on top of merely extracting pixel values.  One
> > library in particular that is applicable to a wide variety of raster
> > data formats is GDAL (geospatial data abstraction library).
> > Integrating this with the SRB and as an EcoGrid service would provide
> > access to a huge variety and volume of spatial data available from
> > various sources, as well as the pgm images.  That library also has
> > numerous methods and examples for windowing, scaling and reprojecting
> > raster data, and so should be fairly easy to integrate in the same
> > manner as you have described below.  It would also provide the
> > significant advantage of providing the foundation of a more
> > standardized mechanism for accessing raster spatial data through the
> > EcoGrid- something that will be useful to a much larger audience
> > compared with the very limited data accessible for the "Why Where"
> > system.
> >
> > cheers,
> >  Dave V.
> >
> > Bing Zhu wrote:
> >
> >> David,
> >>
> >> I am glad that the SRB implementation works fine in getting partial
> >> images
> >> for Niche
> >> Modeling pgm data.
> >>
> >> This is a good step. I just had a meeting with Raja discussing about
> >> moving
> >> this approach to our Ecogrid. Raja suggested to modify the SRB code in
> >> Ecogrid
> >> node to handle the parameters currently implemented in pgm_cut.
> >>
> >> With this approach, the URL used by Niche Modeling in calling our
> >> Ecogrid's
> >> 'get' function
> >> to retrieve partial pgm image will have the syntax similar to a cgi
> >> request.
> >> e.g.
> >>   $ java org.ecoinformatics.ecogrid.client.EcogridQueryClient get  \
> >>
> >> srb://../home/whywhere/.../n00an1.10.pgm?left=10&top=10&width=25&height=30
> >> \
> >>
> >> http://orion.sdsc.edu:8080/ogsa/services/org/ecoinformatics/ecogrid/EcoGridL
> >> evelI
> >>
> >> One of my next tasks in SEEK will be modify the SEEK SRB code to
> >> handle this
> >> for Niche Modeling data. And this approach is also applicable for other
> >> applications which
> >> request partial data transfer.
> >>
> >> Bing
> >>
> >>
> >>
> >> -----Original Message-----
> >> From: hwliu [mailto:hwliu at sdsc.edu]
> >> Sent: Monday, July 12, 2004 12:59 PM
> >> To: bzhu at sdsc.edu
> >> Cc: davids at sdsc.edu
> >> Subject: RE: pgm_cut program
> >>
> >>
> >> Hi, Bing,
> >>    Thanks for your help. I've just tried the program and it worked well.
> >> But, I don't understand the need to use S-command. I just copied
> >> pgm_cut to
> >> my local directory on landscape and it worked even if I don't copy the
> >> S-command directory. By the way, if I want to rebuild the program on
> >> Windows, do I need to download the whole directory of SRB1.2.1?
> >>
> >>                                                           Thanks,
> >>
> >>                                                           Haowei
> >>
> >>
> >> -----Original Message-----
> >> From: Bing Zhu [mailto:bzhu at sdsc.edu]
> >> Sent: Monday, July 12, 2004 10:56 AM
> >> To: hwliu
> >> Cc: davids at sdsc.edu
> >> Subject: RE: pgm_cut program
> >>
> >> Hi Haowei,
> >>
> >> I changed the permission for some directories and files.
> >> Please try it again and let me know if the permission problem still
> >> exists.
> >>
> >> The files are in the directory, /export/home/bzhu/pgm_cut.
> >>
> >> You might also need to use SRB software which is installed in
> >> /export/home/bzhu/SRB2.1.2. Basically, you just need to use
> >> SRB client programs, S-commands, which can be found
> >> in /export/home/bzhu/SRB2.1.2/utilities/bin. To use them, you need
> >> an SRB account. Currently we can use the user, 'whywhere'.
> >> I will be glad to show you how to use SRB software so that
> >> you can test the software with different pgm files stored
> >> under 'whywhere'.
> >>
> >> Sincerely,
> >> Bing
> >>
> >>
> >>
> >>
> >>
> >> -----Original Message-----
> >> From: hwliu [mailto:hwliu at sdsc.edu]
> >> Sent: Monday, July 12, 2004 10:05 AM
> >> To: bzhu at sdsc.edu
> >> Cc: davids at sdsc.edu
> >> Subject: RE: pgm_cut program
> >>
> >>
> >> Hi, Bing:
> >>    I will test the new version of pgm_cut, but I don't have the
> >> permission
> >> to access the directory. Is it possible for you to mail me pgm_cut?
> >>
> >>                                                     Thanks,
> >>
> >>                                                     Haowei
> >>
> >> -----Original Message-----
> >> From: Bing Zhu [mailto:bzhu at sdsc.edu]
> >> Sent: Friday, July 09, 2004 5:48 PM
> >> To: davids at sdsc.edu
> >> Cc: Seek-Dev; Arcot Rajasekar; Matt Jones
> >> Subject: pgm_cut program
> >>
> >> David,
> >>
> >> I modified the pgm_cut.c code to read pgm files stored in SRB storage
> >> place.
> >>
> >> The modified pgm_cut.c can be found in the directory,
> >> /export/home/bzhu/pgm_cut,
> >> in landscape machine.
> >>
> >> Here is an example of running 'pgm_cut' to get partial image from a
> >> pgm file
> >> in SRB.
> >>
> >>  $ pgm_cut 0 0 20 20
> >> /home/whywhere.seek/ei/Data/Terrestrial/n00an1.10.pgm
> >>
> >> Note that I have re-uploaded whywhere data using a new SRB account,
> >> 'whywhere',
> >> as we discussed last time. The new uploaded data, along with their
> >> metadata,
> >> is in the collection, /home/whywhere.seek/ei/Data/Terrestrial.
> >>
> >> Here is the whywhere account info.
> >> user name: whywhere
> >> password: I will send you in another mail.
> >> SRB server: srb.sdsc.edu
> >> SRB domain: seek
> >> SRB port: 6613
> >>
> >> I'd like to test it next Monday. Will you be in office next Monday?
> >>
> >> Sincerely,
> >> Bing
> >>
> >>
> >>
> >> _______________________________________________
> >> seek-dev mailing list
> >> seek-dev at ecoinformatics.org
> >> http://www.ecoinformatics.org/mailman/listinfo/seek-dev
> >>
>
>




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