RETRO (vipl) functions
LIBRARY ROUTINE
lvsamp - Sample an image along an arbitrary line.
LIBRARY CALL
int lvsamp(
xvimage *image,
xvimage **line,
int px1,
int py1,
int px2,
int py2,
int n)
INPUT
- image - pointer to image to be sampled
- line - pointer to image pointer to receive the output image
- px1 - X coordinate of start point
- py1 - Y coordinate of start point
- px2 - X coordinate of end point
- py2 - Y coordinate of end point
- n - number of samples to generate between the endpoints
OUTPUT
- line - xvimage pointer indicated by line is attached
to the new image
RETURN VALUE
TRUE (1) on success, FALSE (0) on failure
DESCRIPTION
NOTE: the lvsamp function will be removed in the future.
lvsamp functionality is replaced by the
lksampline() function in the DATAMANIP::kdatamanip
library. Additional input parameters are required by
lksampline().
Given an image of arbitrary size and a line through
that image, sample the image along the line. The
sampling interval is independent of image size and
line orientation. The value at each sample point is
obtained by bilinear interpolation.
The first sample point is precisely at the starting
point and the final sample is precisely at the ending
point.
ADDITIONAL INFORMATION
none
EXAMPLES
none
SIDE EFFECTS
none
RESTRICTIONS
lvsamp will only work on images of type FLOAT.
MODIFICATION
6-Feb-91 Scott Wilson - Cleaned up for installation,
completed documentation.
8-Feb-91 Scott Wilson - changed length to n, added
pixel size stuff.
10-Feb-91 Scott Wilson - re-wrote the entire inner
loop - the original had bugs
and did not handle the boundary
conditions.
20-Feb-91 Scott Wilson - corrected pixel size computation bug.
FILES
$RETRO/objects/library/vipl/src/lvsamp.c
SEE ALSO
vipl(3)
COPYRIGHT
Copyright (C) 1993 - 1997, Khoral Research, Inc. ("KRI") All rights reserved.