## "Fossies" - the Fresh Open Source Software Archive

### Source code changes of the file "help/en_US/curvature.xml" betweensip-0.5.6.tar.gz and sip-0.12.1.tar.gz

About: SIP (Scilab Image Processing) toolbox to do imaging tasks such as filtering, blurring, edge detection, thresholding, histogram manipulation, segmentation, mathematical morphology, color image processing, etc.

curvature.xml  (sip-0.5.6):curvature.xml  (sip-0.12.1)
skipping to change at line 62 skipping to change at line 62
<listitem> <listitem>
a double number, the time between samples (delta t), and defaults to 1. a double number, the time between samples (delta t), and defaults to 1.
</listitem> </listitem>
</varlistentry> </varlistentry>
</variablelist> </variablelist>
</refsection> </refsection>
<refsection> <refsection>
<title>Description</title> <title>Description</title>
<para> <para>
Function using FFT and a formula from differential geometry. </para> Function <literal>curvature</literal> calculates the curvature at each point o f a binary contour, using FFT and a formula from differential geometry. </para>
</refsection> </refsection>
<refsection> <refsection>
<title>Examples</title> <title>Examples</title>
<programlisting><![CDATA[ <programlisting><![CDATA[
initial_dir = PWD; initial_dir = PWD;
chdir (SIPDIR + 'images'); chdir (SIPDIR + 'images');
clf clf
imshow(Img,2); imshow(Img,2);
k = curvature(Img,13); // 13 sigma (shape is smoothed so curvature exist s) k = curvature(Img,13); // 13 sigma (shape is smoothed so curvature exist s)
clf clf
plot(k) plot(k)
xlabel('curve sample id')
ylabel('curvature')
// //
// observe there are six curvature peaks, // observe there are six curvature peaks,
// corresponding to the six peaks of the star. There // corresponding to the six peaks of the star. There
// is one peak half at 0 and half at about 450. // is one peak half at 0 and half at about 450.
// That's because the parametrization of // That's because the parametrization of
// the contour started at the highest peak and // the contour started at the highest peak and
// terminated there. Note also that the shape had to // terminated there. Note also that the shape had to
// be considerably smoothed so the curvature doesn't // be considerably smoothed so the curvature doesn't
// blow up at the very sharp peaks of the star. // blow up at the very sharp peaks of the star.
// //
chdir(initial_dir); chdir(initial_dir);
]]></programlisting> ]]></programlisting>
</refsection> </refsection>
<para><emphasis role="bold">Original image and the curvature function of its (Ga
ussian-smoothed) boundary curve:</emphasis></para>
<para><imagedata fileref="../../images/star.bmp" />
<imagedata fileref="../images/curvature-plot.png" />
</para>
<refsection> <refsection>
<title>References</title> <title>References</title>
<para> <para>
"Shape Analysis and Classification", L. da "Shape Analysis and Classification", L. da
F. Costa and R. M. Cesar Jr., CRC Press. F. Costa and R. M. Cesar Jr., CRC Press.
</para> </para>
<para> <para>
"Differential Geometry of Curves and Surfaces", Manfredo "Differential Geometry of Curves and Surfaces", Manfredo
P. do Carmo, Prentice Hall, 1976. P. do Carmo, Prentice Hall, 1976.
</para> </para>
skipping to change at line 114 skipping to change at line 121
<refsection><title>Authors</title><simplelist type="vert"> <refsection><title>Authors</title><simplelist type="vert">
<member>Ricardo Fabbri &lt;ricardofabbri[at]users.sf.net&gt;</member> <member>Ricardo Fabbri &lt;ricardofabbri[at]users.sf.net&gt;</member>
</simplelist></refsection> </simplelist></refsection>
<refsection><title>Availability</title> <refsection><title>Availability</title>
<para>http://siptoolbox.sf.net </para> <para>http://siptoolbox.sf.net </para>
</refsection> </refsection>