ll_edges Extract maximal meaningful edges (contrasted pieces of level lines) from a Fimage
ll_edges [-e eps] [-s step] [-p p] [-t tree] [-z] in out
-e eps : -log10(max. number of false alarms), default 0
-s step : quantization step (bilinear), default 1.
-p p : sampling precision (bilinear), default 2
-t tree : use a precomputed FLST tree
-z : use zero order instead of bilinear interpolation
in : input Fimage
out : output edges (Flists)
Flists ll_edges (in , tree , eps , step , precision , z )
Fimage in ;
Shapes tree ;
float *eps , *step ;
int *precision ;
char *z ;
This modules computes all the level lines of an image
(with the same options
ll_extract module) and keeps the most contrasted parts of them.
The detection is made using a thresholding function balancing between
the minimum contrast (gradient norm) along each part and the
corresponding length of the curve. This function ensures
that at most 10-eps false detections could occur by chance
with independent random gradient values (see [DMM01]).
Notice that contrary to the
ll_boundaries detection, this
module can detect non-closed level lines, since each subpart of each
level line is considered.
The result is a collection of curves stored in a Flists structure.
fderiv, fhisto, flst, flstb_boundary, flst_bilinear, flst_boundary, flstb_quantize, fsaddles, sintegral.
Last Modification date : Thu Nov 29 20:23:56 2001