fsaddles Position and value of saddle points in bilinear interpolation
fsaddles image saddles .
image : Input fimage
saddles : Output fimage of saddle points
. (screen output) : Number of saddle points
int fsaddles (pImage , pSaddlesImage )
Fimage pImage , pSaddlesImage ;
This module computes the values at the saddle points in a bilinear interpolated image. The resulting image has one column and one line missing compared to the original image. The value at (i, j) is the one at the saddle point in the dual pixel of corners (i, j), (i + 1, j), (i, j + 1) and (i + 1, j + 1) if there is one, and FLT_MAX (defined in math.h) if there is no saddle point inside the dual pixel. A more appropriate value would have been NAN (Not A Number), but this value is not always defined in math.h.
As the resulting image contains values (or rather non-values) not easily representable, it is not appropriate for viewing via the module fview for example.
This module is mainly called by the module flst_bilinear.
flstb_dualchain, flst_bilinear, flstb_tv, ll_boundaries2, ll_boundaries, ll_edges, ll_extract.
Last Modification date : Thu Nov 29 20:23:56 2001