Help for RESSAR77

PURPOSE:  RESSAR77 is a VICAR applications program which removes the reseau,
fiducial marks, and camera blemishes from Voyager images.  The program may also
be used to remove small circular areas as specified by the user.

EXECUTION:

    RESSAR77  INP=(PIC,RES,BLM)  OUT=OPIC  user-parameters
where
    PIC is the input image.  PIC must be an 800x800 geometrically uncorrected
        Voyager image in either byte or halfword (16-bit integer) format.  The
        entire image must be processed (i.e. the VICAR size field is ignored).
    RES is a record containing the reseau locations for PIC.  RES may be created
	by program RESLOC (see example below).
    BLM is an optional Blemish Location File.  BLM contains the location and
        size of each blemish for the camera used to acquire the input image.
        Blemish files may be created using program BLEMFIX.  If specified, the
        camera blemishes are also removed.
    OPIC is the output image.  OPIC is identical to the input image, except that
        all reseau marks, fiducial marks, and camera blemishes have been
        removed.  (Note, however, that keywords KEEPRESE or KEEPFIDU may be
        used to suppress the removal of the reseau and/or fiducial marks).
OPERATION:

Each object (reseau mark, fiducial mark, or blemish) is removed by interpolating
over the pixels on its boundary.

The line-sample location of each reseau mark is obtained from the input reseau
record.  The exact position of each fiducial mark and camera blemish is deter-
mined by its known offset from specific reseau marks.  Consequently, the input
reseau record is also used to calculate the position of each fiducial mark and
camera blemish.

Reseau marks and camera blemishes are treated as circular areas.  All reseau
marks are assumed to be the same size, as specified by the RADIUS parameter
(default=5 pixels).  The Blemish Location File contains the following data for
each camera blemish: 1) reference reseau mark number, 2) line-sample offsets
from reseau mark, and 3) radius.

Fiducial marks are the dark rectangular marks appearing in the four corners of
the image.  Each fiducial mark is 13 pixels wide and 55-65 pixels long.

Because line 1 of all VGR images generally contains data that is either
saturated or noisy, this line is ignored and allowed to pass untouched.

A special problem arises with those reseau marks which lie near the center of
each fiducial mark.  In order to avoid using pixels in the fiducial mark when
deleting the reseau via interpolation, the fiducial mark removed before
processing neighboring reseau marks.  Samples within a distance of 7 pixels of
these reseau mark are not used in the interpolation.  If KEEPFIDUcial is
specified, the above mentioned reseau marks will not be deleted.

EXAMPLE:

    DCL  ASSIGN  UD2:[CCA314.VGR2]BLEMLOC.WA  BLEM	!Point to blemish file
    RESLOC  (PIC,UD4:[CCA314.VGR]RESN.FIL)  RES		!Locate the reseau
    RESSAR77  (PIC,RES,BLEM)  OPIC

PROGRAM HISTORY:

WRITTEN BY: Gary Yagi      Aug. 27, 1980
COGNIZANT PROGRAMMER: Gary Yagi, Aug 89
REVISION:
 10 Oct 02   GMY    Port to Linux (RESSAR77_LINUX)
  5 Aug 89   GMY    Increase maximum number of blemishes to 1000.
 16 JUN 89   GMY    Handle new format of blemish files created by BLEMFIX
		    Rewrite help file.
  9 JAN 89   SP     Changed to remove circles & blemishes even if reseaux are
                    to be kept.  Prevent extrapolation limits going beyond
                    edge of image for fiducials.
 27 MAR 87   SP     Removed statement that changed ns incorrectly for halfword
                    images.  Changed loop control from NLINE .GT. NS+NLIC TO
                    NLINE .GT. NL+NLIC
 29 OCT 86   SP     Corrected handling of defaults for camera and centers.
 23 OCT 86   JRS    Converted to VICAR2 param I/O.  Image I/O already converted.
 14 APR 83   CCA    Converted to vax
 13 JAN 81   CCA    Implement 3rd input for blem removal
 27 AUG 80   GMY    Initial release