| Description: The inv_lookup_table_file_name element identifies the name of the CRISM file that gives the 12-bit DN value replacing each 8-bit DN value if lossy compression was performed (if compression_type=8_BIT). The inverse lookup table file is a nine-column, 4095-row text file. Column 1 gives each 8-bit value, 0 through 255. Columns 2 through 9 give the 12-bit values that replace them if lookup tables 0 through 7, respectively, were selected for data acquisition. Lookup tables are selected on a line by line basis. Which table is used for each line is indicated in the pixel-processing descriptive file named in pixel_proc_file_name. |