readbackplane Documentation

readbackplane - Read backplane of ISIS cube file 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 READISIS and WRITEISIS routines.)


PRO READBACKPLANE, FILE, BACKNAME, DATA, $
  SFROM=sfrom, SPECIAL=special

;	-----------------------------------
;	|    R E A D B A C K P L A N E    |
;	-----------------------------------
;
;  This procedure reads pixel data from a BACKPLANE of the ISIS cube
;  file specified by the FILE parameter.  The BACKNAME parameter
;  specifies the name of the Backplane to read.  This can be specified
;  with either upper-case or lower-case characters.  (The backplane
;  name is not case-sensitive.)
;
;  The Backplane 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 and LINE is
;  the second 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 Backplanes that are stored in
;  either 8-bit, 16-bit, or 32-bit format.  If the Backplane contains 8-bit
;  or 16-bit data, then the BAND_SUFFIX_BASE and BAND_SUFFIX_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
;  spatial-spatial (SAMPLE/LINE) area of the cube.  If this is not specified,
;  a default SFROM=' ' is assumed, which selects the entire spatial-spatial
;  area.
;
;  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
;