Image conversion among GRASS, ERDAS, PCI

[Wang Song]

	GRASS users sometimes need to exchange the imagery data between GRASS 
raster format and other image processing package supported formats, such as
ERDAS and PCI, etc. I would like to share some thoughts about general methods
to transfer imagery data between GRASS and ERDAS or PCI.

	(1) Interface between GRASS and ERDAS:

	    Special interface:

            ERDAS --> GRASS: Use GRASS command r.in.erdas which requires
                             ERDAS image file in 7.3 version format.

            GRASS --> ERDAS: ERDAS command RDGRASS converts 8-bit uncompressed
                             GRASS raster file into ERDAS GIS files.

            General Interface: 

            ERDAS --> GRASS: Use ERDAS command DPDATA to convert ERDAS image
                             data to the general image binary format, load it
                             directly into GRASS LOCATION cell subdirectory. 
                             Then create a cellhd file with the information
                             provided by ERDAS command LISTIT.

                             If the converted ERDAS file contains multi-band
                             imagery, you need to use GRASS i.tape.other to
                             load it into a GRASS image group.

            GRASS --> ERDAS: Preparation: Directly copy a GRASS raster file from
                             $LOCATION/cell subdirectory into your current 
                             directory. Also, copy the cellhd file for the 
                             reference. If GRASS raster data is in compressed 
                             format, you need to uncompress it with 
                             r.compress -u.
                       
                             Use ERDAS program LDDATA to convert either 8 or
                             16 bits GRASS binary raster data into ERDAS. All
                             parameters required by LDDATA has been defined in
                             GRASS raster header file.

	(2) Interface between GRASS and PCI (5.1 version):

            Special Interface: NO

            General Interface:

            PCI --> GRASS:   Use PCI Generic File transfer command IMAGEWR to 
                             Write the PCIDSK file into a generic image file
                             format without header in it. Then move this file 
                             directly into GRASS $LOCATION/cell directory and
                             create a cell header file with the information 
                             provided by the parameter file to run IMAGEWR.

            GRASS --> PCI:   Use PCI Generic File transfer command IMAGERD to
                             directly read GRASS raster binary file from
                             $LOCATION/cell directory into PCIDSK image file.
                             The GRASS cell header file provides all necessary
                             information to run IMAGERD in PCI.


 


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 #    #    ##    #    #   ####      Wang Song  (wang)
 #    #   #  #   ##   #  #    #     
 #    #  #    #  # #  #  #          Center for Advanced Spatial Technologies
 # ## #  ######  #  # #  #  ###     12 Ozark Hall
 ##  ##  #    #  #   ##  #    #     University of Arkansas
 #    #  #    #  #    #   ####      Fayetteville, AR 72701

INTERNET:  wang at cast.uark.edu      Tel: (501) 575-6159
                                   FAX: (501) 575-3846

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