Level 2 Help for TRACKER3

INP

The input images to acquire tiepoints from.

First is the left or reference image.
      If there is no third input this will have a regular grid. 
Second is the right image.
      If there is no third input this will have an irregular grid.
Third is an optional tiepoints file to be used as initial input values.


OUT

Output tiepoint file .
At the moment this is a mark file with 512 byte records and 32 tiepoints per
record in the order left_line left_sample right_line right_sample, left_...
all float format.


ASCIIFILE

Name of the optional output ascii tiepoints file. Default is no ascii file is
produced. (Default name is "NONE").
If created this file will be in the same order as the binary mark file
but will contain one record per tiepoint. 
All data will be in floating point format, possibly extended precision.
It is intended that records will contain the following 9 columns:
line1 samp1 line2 samp2 dn1 dn2 X Y Z
Tracker3 will fill the first 6 columns:
line1 samp1 line2 samp2 dn1 dn2
Where line1 & samp1 are the left image coordinates.
Where line2 & samp2 are the right image coordinates.
Where dn1 & dn2 are the left & right intensities.


CORREL

The correlation scheme to use. Your options are:
LINEAR (Exhaustive correlation on integral pixel boundaries).
AMOEBA (Simplex deterministic downhill search method).
ANNEAL (Annealing non-deterministic search method).
LINAMO (LINEAR followed by AMOEBA).
ANNAMO (ANNEAL followed by AMOEBA).

See the method description.


NLW

Number of lines in the left image template.
This is the reference area or correlation size.
Should be an odd number.


NSW

Number of samples in the left image template.
This is the reference area or correlation size.
Should be an odd number.


NLAREA

Number of lines in the right image search area.
Usually much larger than NLW.


NSAREA

Number of samples in the right image search area.
Usually much larger than NSW.


GRID

Grid interval in pixels. This is the spacing between columns and rows of 
pixels in the left or reference image. Only used when two input images
are present.


PERCENT

Percentage of the template used in the correlation.

If percent=100 then only one template is used to correlate with.

If percent < 100 then five templates are used, the best one determining
the tiepoint. Template 1 is the standard one. Templates 2-5 permit only
the top,bottom,left,and right PERCENT of the template area to show.
This permits blemishes to be ignored if they are on the edge of the 
correlation area at the expense of five times the overhead.


LIMIT

Number of cycles permitted in the annealing algorithm. As a rule:

1. The fewer cycles the less reliable the result.
2. If ANNEAL is followed by AMOEBA then fewer cycles are needed.
3. If the coefficient search range COEFRANG is large more cycles are needed.


COEFRANG

Range limits of the mapping polynomial for annealing options only.

The polynomial mapping is of the form:
rightline=  C1*leftsample+C2*leftline+C3
rightsample=C4*leftsample+C5*leftline+C6
If you specify: coefrang=(.8,1.2,-.35,.35) then
-.35  < C1 < .35
-.35  < C5 < .35
.8    < C2 < 1.2
.8    < C4 < 1.2
Coefficient solutions will be restricted to this range.

The defaults (above example) permit rotations either way of up to 
about 20 degrees, and scaling of about 20 percent.
ANNEAL and ANNAMO options only.


QUALITY

Only permit tiepoints to be placed into the output file if their correlation
quality exceeds QUALITY. Quality is computed for each corralation and is
a number from 0 (no correlation at all) to 1 (perfect correlation).


ZERO

Reject correlation areas if any of the corners are zero dn.
This permits the zero region outside map projected images to be detected
and not included in correlations.
Whether zero is specified or not all areas which are of the same dn 
(flat fields) are rejected anyway.


PRINT

Print tiepoints and their qualities.


EXTEND

If there are three input files the initial tiepoints will be obtained from 
the third input. The default is to use the left and right tiepoint pairs for
the first and second input files respectively. If however you wish to chain
existing tiepoints through successive images (to track points ) the EXTEND
option will place the right tiepoint side on the FIRST input file and then
create a copy of this point for the second input file. For example, if you had
a movie sequence with images a b c d you would first create a grid of
points with:
tracker3 inp=(a.img,b.img) out=t1.pts grid=40
and then chain them through the other images with:
tracker3 inp=(b.img,c.img,t1.pts) out=t2.pts 'extend
tracker3 inp=(c.img,d.img,t2.pts) out=t3.pts 'extend