IDRISI to GRASS

[Michel Wurtz]

In article QAA15964 at camelot.es.anl.gov, sydelko at es.anl.gov (Pam Sydelko) writes
:
>
>Does anyone know how to import IDRISI files into GRASS?  I thought I saw 
>something on this list server that mentioned a r.in.idrisi command at one
>time, but can't seem to track it down.
>
>Pamela Sydelko
>Argonne National Lab

With IDRISI 4.0 (DOS version), I used the following method:

On the PC running Idrisi

- if files are compressed, use "CONVERT" to uncompress .IMG on IDRISI
  (compressed files are not handled)
- in import/export menu run "GRASSIDR".  Export in  binary format
  this will create 2 dir (cell + cellhd), each containing a file for the
  same dir in grass data tree

On the unix machine running GRASS

- copy the 2 files created on your grass data tree
- if the size of the cell = 1 byte, its OK
- if the cell's size = 2 bytes, you must run
  "dd if=<file in the cell dir> of=<other name> conv=swab" (byte order is diffe
rent)
  and rename the resulting file to the original name.
- run r.support to verify header file (in cellhd) and add a color table.

In fact uncompressed binary .IMG files and uncompressed Grass files have same f
ormat
(except for byte ordering if cell are bigger than 1 byte) and as header files a
re in
ASCII, you can easely create with a text editor

Hoping this will help you,
----
Michel Wurtz - ENGEES, Strasbourg, France