Re: Visit and difax

NOTE: The difax mailing list is no longer active. The list archives are made available for historical reasons.


To manipulate the group 4 fax images, we have used the packages "netpbm" and 

Imagemagick is a freely available piece of software and will convert from the 
fax format to any of its known formats. Here is the Imagemagick url:

They have binary installations on that server which are great. Otherwise if you 
build from source you will have to download the tiff, jpg, mpg libraries 
separately to link against. The distribution is updated fairly regularly which 
is why I prefer it to netpbm.

You can display the fax charts with imagemagick like: display -geom 50% -rotate 
90 difax.fax

or convert formats like: convert difax.fax

The netpbm package is nice for piping straight to a device.  Netpbm is just 
pbmplus with a few additions (can be found on

We do have a difax mailing list which is archived here at:

I searched the list above, and did find an example of a script that is used to 
print the difax images from the IDD using the g3topbm program:

If you have any specific questions about the IDD difax service, Linda Miller 
may be able to provide more information.

Good luck,

Steve Chiswell
Unidata User Support

On Fri, 5 Sep 1997, George Huffman wrote:

Steve - thanks for the chance to actually meet you and to discuss the NUDS.   
Indeed, the problem with the TIF files of DIFAX products was that XV was  
subsetting the file on the fly to get it to fit the screen.  So, the NWS  site 
does have nice maps after all, and firing up xv with the -nolimit option  
allows me to get them out at full resolution.  Is any of the software for  
managing/printing DIFAX charts contained on the Unidata server, or do we  need 
to contact individual sites that have done it?


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