Code covered by the BSD License
 ac_area(acontour)
ac_area: signed area of an active contour
 ac_clipping(acontour, fra...ac_clipping: clipping of an active contour
 ac_deformation(acontour, ...ac_deformation: deformation of an active contour with topology management
 ac_energy(task, varargin)
ac_energy: storage and plot of the energy of a set of active contours and
 ac_evolution(task, about_...ac_evolution: storage, properties, and plot of the evolution of a set of active
 ac_isocontour(frame, leve...ac_isocontour: instantiation of an active contour describing a level set of a frame
 ac_length(acontour)
ac_length: length of an active contour
 ac_mask(acontour, mask_si...ac_mask: conversion of an active contour into a binary mask
 ac_plot(o_axes_handle, ac...ac_plot: plot of an active contour in a window of given height
 ac_resampling(acontour, r...ac_resampling: approximately regular resampling of an active contour using a
 ac_sampling(acontour, o_p...ac_sampling: sampling of an active contour
 ac_segmentation(...
 ac_usage_mean
ac_usage_mean: region competition of meanbased descriptors in grayscale
 ac_usage_mean_basic
ac_usage_mean_basic: region competition of meanbased descriptors in grayscale
 ac_usage_minlength
ac_usage_minlength: curvature flow
 ac_validity(acontour)
ac_validity: check for validity of an active contour
 gi_acontour(task, varargin)
gi_acontour: graphical interface for ac_segmentation
 gi_shape(varargin)
gi_shape: graphical interface for instantiating a polygon, a spline, or a mask
 p_scaling(unscaled, o_fac...
 po_circle(center, radius,...po_circle: instantiation of a closed polygon sampling a circle
 po_ellipse(center, radii,...po_ellipse: instantiation of a closed polygon sampling an ellipse
 po_isocontour(frame, leve...po_isocontour: instantiation of a (set of) closed polygon(s) sampling a level set of a frame
 po_mask(polygon, mask_size)
po_mask: conversion of a closed polygon into a binary mask
 po_orientation(polygon, o...po_orientation: orientation of a closed polygon as a positive or negative real number
 po_plot(polygon, o_window...po_plot: plot of an open or a closed polygon in a window of given height
 po_rectangle(center, leng...po_rectangle: instantiation of a closed polygon sampling a rectangle
 po_rouctangle(center, len...po_rouctangle: instantiation of a closed polygon sampling a chamfered rectangle
 po_simple(polygon)
po_simple: test of closed polygon (non) selfintersection
 po_square(center, width, ...po_square: instantiation of a closed polygon sampling a square
 Contents.mActive Contour Toolbox
 Contents.mPolygon Toolbox

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Active Contour Toolbox
by
Eric Debreuve
05 Jul 2006
(Updated
05 Jul 2006)
This toolbox provides some functions to segment an image or a video using active contours

po_circle(center, radius, number_of_edges, resolution)

function circle = po_circle(center, radius, number_of_edges, resolution)
%po_circle: instantiation of a closed polygon sampling a circle
% p = po_circle(c, r, n, s) computes a closed polygon sampling the circle of
% center c and radius r with either n regularly spaced vertices (or
% equivalently n edges) or a vertex every s pixels. Resolution s is used
% unless n is greater than or equal to 3. s does not have to be an integer.
%
%See also polygon.
%
%Polygon Toolbox by Eric Debreuve
%Last update: June 13, 2006
if number_of_edges < 3
number_of_edges = round(2 * pi * radius / resolution);
if number_of_edges < 3
number_of_edges = 3;
end
end
sampling_angles = 2 * pi / number_of_edges * (number_of_edges:1:1);
circle = [center(1) + radius * sin(sampling_angles); ...
center(2) + radius * cos(sampling_angles)];
circle = [circle circle(:,1)];


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