Skip to content
Snippets Groups Projects
Commit e5b79712 authored by even's avatar even
Browse files

Article: conclusion

parent f8133ed0
No related branches found
No related tags found
No related merge requests found
\section{Conclusion and perspectives}
Gains importants en efficacit\'e.
In this paper we introduced a new edge detector based on a local analysis of
the image gradient and on the use of blurred segments to vehiculate an
estimation of the edge thickness.
It relies on directional scans of the image around maximal values of the
gradient magnitude, that have previously been presented in a former paper.
Despite of good performances obtained compared to existing detection methods
found in the literature, the former approach suffers of two major drawbacks.
It does not estimate the edge thickness so that many outliers are inserted
into the blurred segment and the provided estmation of the edge orientation
is biased.
Then the scan direction is derived from a bounded blurred segment, that
inevitably restricts its value to a finite set, so that long edges may be
not completely detected.
We solved these limitations through two new concepts:
first the adaptive directional scans continuously that adjust the scan strip
to the detected blurred segment direction;
then the control of the assigned width based on the observation of the
blurred segment thickenning in the early stage of its expansion.
Tentative d'estimation de la largeur du segment, qui fiabilise
l'estimation de l'orientation (plus de segments en travers).
Expected gains in execution time linked to the suppression of a useless
repetition of the fine tracking stage were confirmed by the experimental
campaign both in supervised and unsupervised contexts.
The residual weakness is the high sensitivity to the initial conditions
despite of the valuable enhancement brought by the duplication of the
initial detection.
Disturbing gradient perturbations in the early stage of the edge expansion,
possibly due to the presence of close edges, can deeply affect the output
blurred segment.
In supervised context, the user can easily select a favourable area where
the awaited edge is dominant.
But this default remains quite sensible in unsupervised context.
Scans directionnels adaptatifs : une solution au probl\`eme de
la non pr\'edictibilit\'e de l'orientation.
D\'efauts persistants :
\begin{itemize}
\item L'\'epaisseur trouv\'ee n'est pas certifi\'ee.
\item Le r\'esultat d\'epend des conditions initiales.
Ca reste une m\'ethode instable, m\^eme si la duplication de la premi\`ere
\'etape a permis de gagner en stabilit\'e.
\item On n'est pas \`a l'abri d'un contour voisin qui vient perturber
la d\'etection initiale ou l'affinement.
Les filtres en fin de tracking sont l\`a pour soigner, pas pour gu\'erir.
\end{itemize}
Perspectives : validation sur contextes applicatifs.
In future works, we intend to provide some protection against this drawback
by scoring the detection result on the base of a characterization of the
initial context.
Then experimental validation of the consistency of the estimated
width and orientation values on real situations are planned in
different application fields.
%\section*{Acknowledgements}
......@@ -68,8 +68,8 @@ detectors with the input strokes of \RefFig{fig:buro}.}
In the second series of tests, we compare the execution times of both detectors
for the automatic detection of edges on a set of test images. We display the
results for one of them (\RefFig{fig:auto}). X (resp. Y) blurred segments are
extracted with the former (resp. new) detector on all images. The
results for one of them (\RefFig{fig:evalAuto}). X (resp. Y) blurred segments
are extracted with the former (resp. new) detector on all images. The
average execution time is X ms for the former detector, and Y ms for the
new detector.
......@@ -81,7 +81,7 @@ new detector.
\end{tabular}
\caption{Automatic edge detections on one of the test images with the
former detector on the left, and the new detector on the right.}
\label{fig:auto}
\label{fig:evalAuto}
\end{figure}
The former detector do not estimate the edge width, but just circumscribes
......
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment