Help for REGISTER

PURPOSE:
To autonomously register N images by translation only.
Register performs a sigle correlation in the center of the image. The
correlation is about 50 by 50 over a widow about 100 by 100. Your images
must be pre registered to within 25 pixels.

EXECUTION STATEMENT:
register inp=(x1,x2,...xn) out=(y2,...,yn)
where:
x1-xn are n input images
y2-yn are n-1 output images corresponding to x2-xn.

NOTE: An ascii file will be generated called "register.table" which contains
the line and sample shifts of all the images. The file has 2 columns:
line_shift sample_shift.

METHOD:
Register selects a large region near the picture center and correlates a
single tiepoint for each input image relative to the first input.
The first image is used as the reference and is not copied to the output.

  The Gruen correlation scheme used here permits distortions between 
correlation areas of the form:
newline=line*A+sample*B+C
newsamp=line*D+sample*E+F
The task of the correlator is to determine the coefficients A-F which permit 
the best correlation value.

Poor correlations cause the images to be copied.

PROGRAM HISTORY

Cognizant programmer: Jean Lorre

Revisions: 
  2019-08-06 Walt Bunch - IDS-7923 - replaced sprintf calls, misc -Wall cleanup,
                          added enable-log to tst.pdf, added seed to tst gausnois
                          for test repeatability.
  2019-09-06 Walt Bunch - IDS-7922 - initialized some variables. 

PARAMETERS: