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Article: figures 4 and 5 fusionned

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...@@ -53,10 +53,11 @@ The fine tracking step consists on building and extending a blurred segment ...@@ -53,10 +53,11 @@ The fine tracking step consists on building and extending a blurred segment
$\mathcal{B}'$ based on points that correspond to local maxima of the $\mathcal{B}'$ based on points that correspond to local maxima of the
image gradient, ranked by magnitude order, and with gradient direction image gradient, ranked by magnitude order, and with gradient direction
close to a reference gradient direction at the segment first point. close to a reference gradient direction at the segment first point.
At this refinement step, the control of the assigned width is applied At this refinement step, a control of the assigned width is applied
and an adaptive directional scanner based on the found position $C$ and and an adaptive directional scanner based on the found position $C$ and
direction $\vec{D}$ is used in order to extends the segment in the direction $\vec{D}$ is used in order to extends the segment in the
appropriate direction. appropriate direction. These two improvements are described in the
following sections.
The fine track output segment is finally filtered to remove artifacts The fine track output segment is finally filtered to remove artifacts
and outliers, and a final blurred segment $\mathcal{B}''$ is provided. and outliers, and a final blurred segment $\mathcal{B}''$ is provided.
...@@ -67,34 +68,14 @@ The blurred segment is searched within a directional scan with a position ...@@ -67,34 +68,14 @@ The blurred segment is searched within a directional scan with a position
and an orientation approximately provided by the user, or blindly defined and an orientation approximately provided by the user, or blindly defined
in unsupervised mode. in unsupervised mode.
Most of the time, the detection stops where the segment escapes sideways Most of the time, the detection stops where the segment escapes sideways
from the scan strip (\RefFig{fig:escape}). from the scan strip (\RefFig{fig:escape} a).
A second search is then run using another directional scan aligned A second search is then run using another directional scan aligned
on the detected segment. on the detected segment (\RefFig{fig:escape} b).
However, even in case of a correct detection, the estimated orientation However, even in case of a correct detection, the estimated orientation
of the segment is subject to the numerization rounding, of the segment is subject to the numerization rounding,
and the longer the real segment to detect, the higher the probability to and the longer the real segment to detect, the higher the probability to
fail again on a blurred segment escape from the directional scan. fail again on a blurred segment escape from the directional scan.
\begin{figure}[h]
\center
\begin{tabular}{c@{\hspace{0.2cm}}c@{\hspace{0.2cm}}c}
\includegraphics[width=0.31\textwidth]{Fig_notions/escapeFirst_zoom.png} &
\includegraphics[width=0.31\textwidth]{Fig_notions/escapeSecond_zoom.png} &
\includegraphics[width=0.31\textwidth]{Fig_notions/escapeThird_zoom.png}
\end{tabular}
\begin{picture}(1,1)(0,0)
\put(-314,-12){a)}
\put(-200,-12){b)}
\put(-86,-12){c)}
\end{picture}
\caption{Aborted detections on side escapes from the directional scan
during the initial tracking step (a) and during the fine tracking
step (b), and complete detection using an adaptive directional
scan (c). The input selection is drawn in red color, the scan
strip bounds in blue and the detected blurred segment in green.}
\label{fig:escape}
\end{figure}
%Even in ideal situation where the detected segment is a perfect line, %Even in ideal situation where the detected segment is a perfect line,
%its width is never null as a result of the discretization process. %its width is never null as a result of the discretization process.
%The estimated direction accuracy is mostly constrained by the length of %The estimated direction accuracy is mostly constrained by the length of
...@@ -155,23 +136,55 @@ width $\varepsilon$ ($k$ is a constant arbitrarily set to 4). ...@@ -155,23 +136,55 @@ width $\varepsilon$ ($k$ is a constant arbitrarily set to 4).
The last clause expresses the update of the scan bounds at iteration $i$. The last clause expresses the update of the scan bounds at iteration $i$.
Compared to static directional scans, the scan strip moves while Compared to static directional scans, the scan strip moves while
scan lines remain fixed. scan lines remain fixed.
An example of adaptive directional scan is given in \RefFig{fig:adaption}. This behavior ensures a complete detection of the blurred segment even
when the orientation is badly estimated (\RefFig{fig:escape} c).
\begin{figure}[h] \begin{figure}[h]
\center \center
\begin{tabular}{c@{\hspace{0.2cm}}c} \begin{tabular}{c@{\hspace{0.2cm}}c}
\includegraphics[width=0.49\textwidth]{Fig_notions/adaptionBounds_zoom.png} \includegraphics[width=0.48\textwidth]{Fig_notions/escapeFirst_zoom.png} &
& \includegraphics[width=0.49\textwidth]{Fig_notions/adaptionLines_zoom.png} \includegraphics[width=0.48\textwidth]{Fig_notions/escapeSecond_zoom.png} \\
\multicolumn{2}{c}{
\includegraphics[width=0.98\textwidth]{Fig_notions/escapeThird_zoom.png}}
\begin{picture}(1,1)(0,0)
{\color{dwhite}{
\put(-260,134.5){\circle*{8}}
\put(-86,134.5){\circle*{8}}
\put(-172,7.5){\circle*{8}}
}}
\put(-263,132){a}
\put(-89,132){b}
\put(-175,5){c}
\end{picture}
\end{tabular} \end{tabular}
\caption{Example of blurred segment detection \caption{Aborted detections on side escapes of static directional scans
using an adaptive directional scan. and successful detection using an adaptive directional scan.
On the right picture, the scan bounds are displayed in red, the The last points added to the left of the blurred segment during
detected blurred segment in blue, and its bounding lines in green. the initial detection (a) lead to a bad estimation of its
The left picture displays the successive scans. orientation, and thus to an incomplete fine detection with
Here the adaption is visible at the crossing of the tile joins.} a classical directional scanner (b). This scanner is
\label{fig:adaption} advantageously replaced by an adaptive directional scanner
able to continue the segment expansion as far as necessary (c).
The input selection is drawn in red color, the scan strip bounds
in blue and the detected blurred segment in green.}
\label{fig:escape}
\end{figure} \end{figure}
%\begin{figure}[h]
%\center
% \begin{tabular}{c@{\hspace{0.2cm}}c}
% \includegraphics[width=0.49\textwidth]{Fig_notions/adaptionBounds_zoom.png}
% & \includegraphics[width=0.49\textwidth]{Fig_notions/adaptionLines_zoom.png}
% \end{tabular}
% \caption{Example of blurred segment detection
% using an adaptive directional scan.
% On the right picture, the scan bounds are displayed in red, the
% detected blurred segment in blue, and its bounding lines in green.
% The left picture displays the successive scans.
% Here the adaption is visible at the crossing of the tile joins.}
% \label{fig:adaption}
%\end{figure}
\subsection{Control of the assigned width} \subsection{Control of the assigned width}
The assigned width $\varepsilon$ to the blurred segment recognition algorithm The assigned width $\varepsilon$ to the blurred segment recognition algorithm
......
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