RETRO (vipl) functions
LIBRARY ROUTINE
lvgettilt - computes the best-fit plane parameters for the input VIFF file
LIBRARY CALL
int lvfindtilt(
xvimage *image,
double *a,
double *b,
double *c)
INPUT
none
OUTPUT
none
RETURN VALUE
TRUE (1) on success, FALSE (0) on failure
DESCRIPTION
lvgettilt & lvfindtilt compute the least-squares best
fit plane for an image. The plane will be given by
f(x,y)=Ax+By+C with the tilt coefficients in inverse
pixels.
lvmafdtilt computes the least-squares best fit plane
for an image with a mask. The plane will be given by
f(x,y)=Ax+By+C with the tilt coefficients in inverse
pixels. The plane coefficients will be computed only
for those pixels enabled by the mask image. If a mask
image is supplied, it MUST be of the same type and
size as the input image.
ADDITIONAL INFORMATION
none
EXAMPLES
none
SIDE EFFECTS
none
RESTRICTIONS
If a mask image is supplied, it MUST be of the same
type and size as the input image.
The lvfindtilt and lvmafdtilt libraries will not work
on BIT or COMPLEX data storage type files. lvfindtilt
and lvmafdtilt will only calculate the tilt of the
first band in a multiband image.
MODIFICATION
Mon Jun 11 16:30:29 MDT 1990 Donna Koechner - updated to
ghostwriter
Wed Mar 20 12:36:43 MET 1991 Jean Pierre Guerin
1- fixed loops to work right with non square images
2- fixed bogus (int) caste
3- fixed incorrect term in calculation of detc
4- corrected pointer increments
25-Sep-91 Scott Wilson - Changed (int) castes to (unsigned
int) castes in byte processing
loop - otherwise can get goofy sign
extension problems.
25-Sep-91 Scott Wilson - Found that the det{A,B,C} eqns were
ALL wrong. Fixed them up after
rederiving the whole mess.
26-Sep-91 Scott Wilson - Fixed incorrect center point
calculation.
FILES
$RETRO/objects/library/vipl/src/lvgettilt.c
SEE ALSO
vipl(3)
COPYRIGHT
Copyright (C) 1993 - 1997, Khoral Research, Inc. ("KRI") All rights reserved.