From 4dc99b679c369e4fa1c732cf7aa7967669e8100a Mon Sep 17 00:00:00 2001 From: even <philippe.even@loria.fr> Date: Wed, 12 Dec 2018 20:07:01 +0100 Subject: [PATCH] Article: blurred segments revisited --- Article/intro.tex | 4 ++-- Article/notions.tex | 24 ++++++++++++++---------- 2 files changed, 16 insertions(+), 12 deletions(-) diff --git a/Article/intro.tex b/Article/intro.tex index 6e472b7..f755bef 100755 --- a/Article/intro.tex +++ b/Article/intro.tex @@ -66,8 +66,8 @@ 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 discrete space is finite, there is necessarily a limit on this direction accuracy. -It results that more steps would be necessary to process higher resolution -images. +It results that more steps would inevitably be necessary to process higher +resolution images. \subsection{Main contritions} diff --git a/Article/notions.tex b/Article/notions.tex index 3819553..a104d45 100755 --- a/Article/notions.tex +++ b/Article/notions.tex @@ -14,10 +14,11 @@ is the set of points $P(x,y)$ of $\mathbb{Z}^2$ that satisfy : $0 \leq ax + by - c < \nu$. \end{definition} -$b/a$ is the slope of $\mathcal{L}$, $c$ its intercept and $\nu$ -its arithmetic width. -When $\nu = max (|a|, |b|)$, $\mathcal{L}$ is the narrowest 8-connected -line and is called a naive line. +The parameters of the digital line are its slope $b/a$, its height $c$ +and its arithmetic width $\nu$. The set of points is organized as a +periodic pattern of length $p = (|a|, |b|)$. +When $\nu = p$, $\mathcal{L}$ is the narrowest 8-connected line +and is called a naive line. \begin{definition} A blurred segment $\mathcal{B}$ of assigned width $\varepsilon$ is a set @@ -32,8 +33,8 @@ segment when adding each point successively. The minimal width $\mu$ of the blurred segment $\mathcal{B}$ is the arithmetical width of the narrowest digital straight line that contains $\mathcal{B}$. -It is also the minimal width of the convex hull, that is computed by -Melkman's algorithm \cite{Melkman87}. +It is also the minimal width of the convex hull of $\mathcal{B}$, +that can be computed by Melkman's algorithm \cite{Melkman87}. The extension of the blurred segment $\mathcal{B}_i$ of assigned width $\varepsilon$ and minimal width $\mu_i$ at step $i$ with a new input point $P_{i+1}$ is thus controlled by the recognition test $\mu_{i+1} < \varepsilon$. @@ -48,11 +49,14 @@ the assigned width $\varepsilon$, then the new input point is rejected.} \label{fig:bs} \end{figure} -At the beginning, a large width $\varepsilon$ is assigned to the +The control of the assigned width $\varepsilon$ is ensured on the +following way. +At the beginning, a large width $\varepsilon_0$ is assigned to the recognition problem to allow the detection of large blurred segments. -Then, when no more aumentation of the minimal width is observed as the segment -grows, the assigned width is fixed to the observed minimal width in order to -avoid the incorporation of spurious outliers in further parts of the segment. +Then, when no more aumentation of the minimal width is observed as the +segment grows ($\mu_{i+\lambda} = \mu_i$), the assigned width is fixed +to the observed minimal width in order to avoid the incorporation of +spurious outliers in further parts of the segment. \subsection{Directional scan} -- GitLab