Skip to content
GitLab
Explore
Sign in
Primary navigation
Search or go to…
Project
2
2019 FBSD
Manage
Activity
Members
Labels
Plan
Issues
0
Issue boards
Milestones
Wiki
Code
Merge requests
0
Repository
Branches
Commits
Tags
Repository graph
Compare revisions
Snippets
Build
Pipelines
Jobs
Pipeline schedules
Artifacts
Deploy
Releases
Package Registry
Model registry
Operate
Environments
Terraform modules
Monitor
Incidents
Analyze
Value stream analytics
Contributor analytics
CI/CD analytics
Repository analytics
Model experiments
Help
Help
Support
GitLab documentation
Compare GitLab plans
Community forum
Contribute to GitLab
Provide feedback
Keyboard shortcuts
?
Snippets
Groups
Projects
Show more breadcrumbs
Kerautret Bertrand
2019 FBSD
Commits
4e514645
Commit
4e514645
authored
6 years ago
by
even
Browse files
Options
Downloads
Patches
Plain Diff
Article: intro revisited
parent
d8df9740
No related branches found
No related tags found
No related merge requests found
Changes
3
Hide whitespace changes
Inline
Side-by-side
Showing
3 changed files
Article/intro.tex
+20
-22
20 additions, 22 deletions
Article/intro.tex
Article/method.tex
+4
-2
4 additions, 2 deletions
Article/method.tex
Article/notions.tex
+7
-5
7 additions, 5 deletions
Article/notions.tex
with
31 additions
and
29 deletions
Article/intro.tex
+
20
−
22
View file @
4e514645
...
...
@@ -37,7 +37,7 @@ blurred segments of fixed width in gray-level images was already introduced.
It is based on a first rough detection in a local area
of the image either defined by the user in supervised context or blindly
explored in automatic mode. The goal is to disclose the presence of an edge.
Therefore
,
a simple test as the gradient maximal value is performed.
Therefore a simple test as the gradient maximal value is performed.
In case of success, refinement steps are run through an exploration of
the image in the direction of the detected edge.
...
...
@@ -48,25 +48,23 @@ untill a correct candidate with an acceptable gradient orientation is found.
Only the gradient information is processed as it provides a good information
on the image dynamics, and hence the presence of edges.
Trials to also use the intensity signal were made through costly correlation
techniques, but they were mostly successful for detecting
object
s with
stable appearance such as metallic
pipe
s
\cite
{
AubryAl17
}
.
techniques, but they were mostly successful for detecting
shape
s with
a
stable appearance such as metallic
tubular object
s
\cite
{
AubryAl17
}
.
Despite of good performances obtained compared to other methods from the
literature, several drawbacks remain.
First, the blurred segment width is not measured, but initially set by the
user to meet the application requirements, so that no quality information
can be derived from the computed segment.
Moreover, the blurred segment hull is left free to shift sidewards, or worst,
to rotate around a thin edge in the image, and the produced orientation
value can be largely biased.
Despite of good performances achieved, several drawbacks remain.
First, the blurred segment width is not measured but initially set by the
user according to the application requirements. The produced information
on the edge quality is rather poor, and especially when the edge is thin,
the risk to incorporate outlier points is quite high, thus producing a
biased estimation of the edge orientation.
Then, two refinement steps are systematically run
to cope with most of the
tested data, although
this is useless when the first detection is successfull.
Beyo
nd, there is no guarantee that this
could treat all kinds of data.
The search direction is fixed by the support vector of the blurred segment
detected at the former step, and because the set of vectors in a bounded
d
iscrete space is finite, there is necessarily a limit on this direction
accuracy.
Then, two refinement steps are systematically run
.
On one hand,
this is useless when the first detection is successfull.
On the other ha
nd, there is no guarantee that this
approach is able to
process larger images.
The search direction relies on the support vector of the blurred segment
d
etected at the former step, and the numerization rounding fixes a limit
on this estimated orientation
accuracy.
It results that more steps would inevitably be necessary to process higher
resolution images.
...
...
@@ -83,10 +81,10 @@ As a side effect, these two major evolutions also led to a noticeable
improvement of the time performance of the detector.
In the next section, the main theoretical notions this work relies on are
introduced
, with a specific focus on the new concept of adaptive directional
scanner.
Then
the
new detector workflow and its
integration into both supervised
and
unsupervised contexts are presented and discussed in
\RefSec
{
sec:method
}
.
introduced
.
Then the new detector workflow, the adaptive directional scanner, the control
of
the
assigned with and their
integration into both supervised
and
unsupervised contexts are presented and discussed in
\RefSec
{
sec:method
}
.
Experiments led to assess the expected increase of performance are decribed
in
\RefSec
{
sec:expe
}
.
Finally achieved results are summarized in
\RefSec
{
sec:conclusion
}
,
...
...
This diff is collapsed.
Click to expand it.
Article/method.tex
+
4
−
2
View file @
4e514645
...
...
@@ -267,7 +267,7 @@ This distinction is illustrated on \RefFig{fig:edgeDir}.
Another option, called multi-detection allows the detection of all the
segments crossed by the input stroke
$
AB
$
.
The multi-detection algorithm is displayed below.
The multi-detection algorithm
(Algorithm 1)
is displayed below.
\input
{
Fig
_
method/algoMulti
}
...
...
@@ -282,6 +282,7 @@ detected blurred segments $\mathcal{B}_j''$ at the end of each successful
detection;
iii) points marked as occupied are rejected when selecting candidates for the
blurred segment extension in the fine tracking step.
Multiple detections of the same edge are thus avoided.
In edge selection mode (
\RefFig
{
fig:edgeDir
}
b), the multi-detection
algorithm is executed twice.
...
...
@@ -341,7 +342,8 @@ segment.
\subsection
{
Automatic blurred segment detection
}
An unsupervised mode is also proposed to automatically detect all the
straight edges in the image. A stroke that crosses the whole image, is
straight edges in the image. The principle of this automatic detection
is described in Algorithm 2. A stroke that crosses the whole image, is
swept in both direction, vertical then horizontal, from the center to
the borders. At each position, the multi-detection algorithm is run
to collect all the segments found under the stroke.
...
...
This diff is collapsed.
Click to expand it.
Article/notions.tex
+
7
−
5
View file @
4e514645
...
...
@@ -67,7 +67,7 @@ DS = \left\{ S_i = \mathcal{D} \cap \mathcal{N}_i \cap \mathcal{I}
\end{array}
\right
.
\right\}
%S_i = \mathcal{D} \cap \mathcal{N}_i, \mathcal{N}_i \perp \mathcal{D}
\end{equation}
In this
express
ion, the clause
In this
definit
ion, the clause
$
\delta
(
\mathcal
{
N
}_
i
)
=
-
\delta
^{
-
1
}
(
\mathcal
{
D
}
)
$
expresses the othogonality constraint between the scan lines
$
\mathcal
{
N
}_
i
$
and the scan strip
$
\mathcal
{
D
}$
.
...
...
@@ -79,7 +79,7 @@ The scans $S_i$ are developed on each side of a start scan $S_0$,
and ordered by their distance to the start line
$
\mathcal
{
N
}_
0
$
with
a positive (resp. negative) sign if they are on the left (resp. right)
side of
$
\mathcal
{
N
}_
0
$
(
\RefFig
{
fig:ds
}
).
The directional scan is iterately pr
oces
sed from the start scan to both ends.
The directional scan is iterately p
a
rsed from the start scan to both ends.
At each iteration
$
i
$
, the scans
$
S
_
i
$
and
$
S
_{
-
i
}$
are successively processed.
\begin{figure}
[h]
...
...
@@ -111,9 +111,11 @@ At each iteration $i$, the scans $S_i$ and $S_{-i}$ are successively processed.
\put
(-60,30)
{$
\mathcal
{
N
}_
8
$}
\put
(-169,8)
{$
\mathcal
{
N
}_{
-
5
}$}
\end{picture}
\caption
{
A directional scan: the start scan
$
S
_
0
$
in blue, odd scans in
green, even scans in red, scan lines bounds
$
\mathcal
{
N
}_
i
$
in
plain lines and scan strip bounds
$
\mathcal
{
D
}$
in dotted lines.
}
\caption
{
A directional scan.
The start scan
$
S
_
0
$
is drawn in blue, odd scans in green,
even scans in red, the bounds of scan lines
$
\mathcal
{
N
}_
i
$
with plain lines and the bounds of scan strip
$
\mathcal
{
D
}$
with dotted lines.
}
\label
{
fig:ds
}
\end{figure}
...
...
This diff is collapsed.
Click to expand it.
Preview
0%
Loading
Try again
or
attach a new file
.
Cancel
You are about to add
0
people
to the discussion. Proceed with caution.
Finish editing this message first!
Save comment
Cancel
Please
register
or
sign in
to comment