Re: pgmtonc.tar.Z

• To: Valentijn Venus <venus@xxxxxx>
• Subject: Re: pgmtonc.tar.Z
• From: Don Murray <dmurray@xxxxxxxxxxxxxxxx>
• Date: Wed, 06 Sep 2006 15:04:39 -0600

Hi Valentijn-

Valentijn Venus wrote:

i'm looking for a utility developed by Unidata in the days of Ynot:
pgmtonc

This utility takes an image in the Portable Gray Map intermediate
format and writes it to a netCDF file. I would like to convert a
shallow waterdepth product from SeaWIFS into a netCDF file to be able
to display and use it in the IDV.

coral reefs shallow waterdepths from SeaWIFS: ftp://ocdist5.sci.gsfc.nasa.gov/pub/seawifs_bathymetry/README

pgmtonc: see
http://www.unidata.ucar.edu/newsletter/1993spr/93sprel.html#article6

quote:

Pbmplus utilities you can get them via anonymous ftp from
ftp.unidata.ucar.edu in the file pub/pbmplus.tar.Z. This compressed
tar file contains all of the Pbmplus utilities, including pgmtonc.
Or, you can FTP it from the contrib directory in the Ynot
distribution account (this will only work if you are a licensed Ynot
user). The file name is pgmtonc.tar.Z. To build the Pbmplus
utilities, you will need the various Pbmplus libraries included in
the tar file, as well as the netCDF library.

Even if you had this file, you'd still need to add in navigation
information since that is not in the file.

Unfortunately, it's no longer on the server. Any ideas/other
solutions?

You could take the PPM version and convert it to a GIF and
then read it into the IDV and use the Navigated Image formula.
However, if I uncompress the PPM file, it's 756 Mb.  I used
ppmtogif to create a GIF which was 103 Mb (36000x7000 pixels).
You could subsample the navigated image with the following
Jython:

def skip(image, skip):
  from ucar.unidata.data.grid import GridUtil
  return GridUtil.subset(image, int(skip))

and have your formula be:

skip(image, numpts[isuser=true])

which would prompt you for the number of points.  I used 100
and displayed it with a Color Shaded Plan view which produced
a blocky image.

By comparison, on my Windows system, it took the Windows Fax
and Picture viewer about 10 minutes to generate the preview of
the full image.

Don
*************************************************************
Don Murray                               UCAR Unidata Program
dmurray@xxxxxxxxxxxxxxxx                        P.O. Box 3000
(303) 497-8628                              Boulder, CO 80307
http://www.unidata.ucar.edu/staff/donm
*************************************************************

• Follow-Ups:
  • Re: pgmtonc.tar.Z
    • From: Rich Signell

• References:
  • pgmtonc.tar.Z
    • From: Valentijn Venus