need help. how to uncompress .img files from magellan Options

[ncc1701d]

Hoping someone can help.
I am trying to uncompress the FMAP .img files which are part of magellans images of venus so I can use a converter program to convert them from sinusodal to cylindrical mapping.

Things I do know is that I can just rename .img to .raw and open in photosho however the converter program newmap.exe which is an old dos program that is provided with the FMAP images requires I think the uncompressed .img files in order to convert sinusodal to cylindrical. I know the .raw didnt work. And I get error saying my .img files are compressed so it wont work.
I know .img files are not cd or dvd image file or so I think becuase I could not open them in MagicISO If they were CD images I would think MagicISO would work but I may be wrong though.
Anyone familiar with what I am trying to do. Any image processing guys out their do this with the magellan FMAPS?
I figure the experts would be here.
thanks

[siravan]

IMG files usually have either a text header or a separate text .lbl file, which you can read using a text editor and figure out what to do with them. A typical example is included here. It basically means that the file is organized into 20682 fixed-length records, each 30776 bytes in length (i.e. total file size is 30776*20682=636509232 bytes). ^IMAGE line means raw data begins at the second record (it is a 1 base system, so the first record is 1, not 0), hence, the image data starts at byte 30776. Here, each pixel is recorded as a 32 bit (SAMPLE_BITS) floating point number (SAMPLE_TYPE=PC_REAL, technically little-endian IEEE 754 floating-point number; in practice, this is the 'float' type in most programming languages). The image dimension is 20681 x 7694 pixels. The data is organized row first, so the first line of data is from byte 30776 to 30776+7694*4-1=61551. You can read it using a raw data import utility (Photoshop has one, I guess Gimp has one too), or if you are prone to write your own code, you can write a quick import program in the language of your choice.

PDS_VERSION_ID = PDS3

/*File format and length */
RECORD_TYPE = FIXED_LENGTH
RECORD_BYTES = 30776
FILE_RECORDS = 20682
^IMAGE = 2

OBJECT = IMAGE
LINES = 20681
LINE_SAMPLES = 7694
BANDS = 1
OFFSET = 0.0
SCALING_FACTOR = 1.0
SAMPLE_BITS = 32
SAMPLE_BIT_MASK = 2#11111111111111111111111111111111#
SAMPLE_TYPE = PC_REAL
MISSING_CONSTANT = 16#FF7FFFFB#
VALID_MINIMUM = -366.22
VALID_MAXIMUM = 1793.79
END_OBJECT = IMAGE