readisis Documentation

readisis - Read ISIS cube file data into an IDL array

This is a routine that can be called from an IDL program and thus can
be used for writing IDL programs that perform specialized processing
of ISIS cube files.  (See also the WRITEISIS routine.)


PRO READISIS, FILE, DATA, $
  SFROM=sfrom, SPECIAL=special

;	-------------------------
;	|    R E A D I S I S    |
;	-------------------------
;
;  This procedure reads pixel data from the ISIS cube file specified by
;  the FILE parameter.  The pixel data are returned in the DATA parameter,
;  which will contain the pixel values in their floating point representation.
;  In the returned DATA array, SAMPLE is the first dimension, LINE is
;  the second dimension, and BAND is the third dimension.  This will
;  always be the organization of the returned data array regardless of
;  the physical storage order for the input cube file.
;
;  This procedure is able to read ISIS cube files that are stored in
;  either 8-bit, 16-bit, or 32-bit format.  If the file contains 8-bit
;  or 16-bit data, then the CORE_BASE and CORE_MULTIPLIER label keyword
;  values are applied to produce the floating point pixel values that are
;  being represented.
;
;  The optional SFROM keyord parameter allows selecting a subarea of the
;  core area of the cube.  If this is not specified, a default SFROM='::1'
;  is assumed, which selects the entire spatial-spatial plane at the
;  first band.  Note that specifying a blank string as the SFROM value
;  will select the entire core area of the cube file.
;
;  The optional SPECIAL keyword parameter allows translating ISIS special
;  pixel values into some other values.  If SPECIAL is not specified, then
;  special pixels are not translated.  If a single value is specified, then
;  all special pixels are translated to that value.  (The value is
;  automatically converted to floating point if needed.)  If five values are
;  provided, then the five types of special pixels are translated to the
;  specified five values.  The order of the values is: NULL,
;  LOW_REPR_SATURATION, LOW_INSTR_SATURATION, HIGH_INSTR_SATURATION, and
;  HIGH_REPR_SATURATION.
;
;  Written by Jim Torson, U.S. Geological Survey, Flagstaff
;