matchpt Documentation

matchpt -  Calculates and records three match points for 2 images

MATCHPT will calculate and record in the label of the FROM file 3
match point values for 2 overlapping images.  For each match point the
following information will be stored in the label of the first image:
(1) a match point number, (2) the sample and line coordinates for a
point on the first image, (3) the image id for the second image, and
(4) the sample and line coordinates for the same point on the second
image.  If 3 match points are not found for a set of images or any
error occurs during the program, the filenames of the 2 files will be
written to NO3FIL. The DOSD parameter controls whether the program
will perform a standard deviation ratio for the area around each
match point.  The idea behind this parameter is to eliminate the
problem of the program selecting "good" match points in areas of the
image that are totally uniform.  If DOSD is YES, the image area used
to register one image to another will have a standard deviation value
calculated for it.  That standard deviation value will then be
ratioed to the standard deviaton of a 9 by 9 subarea with the
sample, line coordinates of the match point as the center.  If this
ratio is less than 0.1 then the match point will be discarded.

Programmer:  Jim Mathews, U.S.G.S., Flagstaff, AZ

Input cube file name
  (default extension is .cub)

NONE

Second input cube file name
  (default extension is .cub)

NONE

Filename for output file for
  files with < 3 match points

"no3match.fil"

Core band to match in first
and second image

1

Fit tolerance factor

0.80

Sample dimension box size

0

Line dimension box size

0

Check offset equal/greater
  than LTOL, STOL

"YES"

Max line tolerance for pixel
  offset

25

Max sample tolerance for pixel
  offset

25

Minimum valid pixel value for
  sub-pixel registration

--

Maximum valid pixel value for
  sub-pixel registration

--

Perform standard deviation
  ratio - YES or NO

"NO"

Disable processing history text
(YES, NO)

NO

Comment for user

" "

ADDITIONAL NOTES:

Parm	Description
FROM	Input cube file name. If the file extension is omitted, then ".cub" will be assumed.
FROM2	Second input cube file name. If blank, use a band from the first input cube.
NO3FIL	Enter the filename for an ascii output file which will contain the names of each pair of images that have less than 3 match points calculated for them.
BAND	Specifies the core band to be used to pick the match points for the first and second images.
FITTOL	The fit tolerance factor in calculating the sample and line locations of the match points. This value is returned from U_CALCREG and determines how good the fit is between the two points.
SBOX	Enter the box size for the sample dimesion. If 0 is entered, the program will calculate and use the maximum box size for the two images.
LBOX	Enter the box size for the line dimesion. If 0 is entered, the program will calculate and use the maximum box size for the two images.
CHKOFF	If this parameter is set to "YES", the program will check to see if the offset calculated for a pair of images is equal to or greater than LTOL and STOL. If it is greater than or equal the program will reject this answer and not record the match point to the label. If this parameter is "NO", this check will not be done and the match point calculated will be considered a good point.
LTOL	The maximum amount of offset in the line dimension the program will use in trying to find a match point for each location chosen
STOL	The maximum amount of offset in the sample dimension the program will use in trying to find a match point for each location chosen
LOW	The minimum valid pixel value that will be used in the sub-pixel registration. If the default (null) is used, the program will set LOW to VALID_MIN4.
HIGH	The maximum valid pixel value that will be used in the sub-pixel registration. If the default (null) is used, the program will set HIGH to VALID_MAX4.
DOSD	This paramter controls whether the standard deviation ratio will be used to determine if a match point is good or not. For more information about how this ratio is calculated see the general help section of this pdf.
HIST	Disable the processing history text. This will improve the efficiency if a large number of images are being matched.
USERNOTE	Specifies a comment that will be entered into the output log file and history entry in the output file.