--- /dev/null
+## Copyright (C) 2010 Soren Hauberg
+##
+## This program is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation; either version 3 of the License, or
+## (at your option) any later version.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program; If not, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn {Function File} {@var{props} = } regionprops (@var{BW})
+## @deftypefnx {Function File} {@var{props} = } regionprops (@var{BW}, @var{properties}, @dots{})
+## Compute object properties in a binary image.
+##
+## @code{regionprops} computes various properties of the individual objects (as
+## identified by @code{bwlabel}) in the binary image @var{BW}. The result is a
+## structure array containing an entry per property per object.
+##
+## The following properties can be computed.
+##
+## @table @t
+## @item "Area"
+## The number of pixels in the object.
+## @item "EulerNumber"
+## @itemx "euler_number"
+## The Euler number of the object (see @code{bweuler} for details).
+## @item "BoundingBox"
+## @itemx "bounding_box"
+## The bounding box of the object. This is represented as a 4-vector where the
+## first two entries are the @math{x} and @math{y} coordinates of the upper left
+## corner of the bounding box, and the two last entries are the width and the
+## height of the box.
+## @item "Extent"
+## The area of the object divided by the area of the bounding box.
+## @item "Perimeter"
+## The length of the boundary of the object.
+## @item "Centroid"
+## The center coordinate of the object.
+## @item "PixelIdxList"
+## @itemx "pixel_idx_list"
+## The indices of the pixels in the object.
+## @item "FilledArea"
+## @itemx "filled_area"
+## The area of the object including possible holes.
+## @item "PixelList"
+## @itemx "pixel_list"
+## The actual pixel values inside the object. This is only useful for grey scale
+## images.
+## @item "FilledImage"
+## @itemx "filled_image"
+## A binary image with the same size as the object's bounding box that contains
+## the object with all holes removed.
+## @item "Image"
+## An image with the same size as the bounding box that contains the original pixels.
+## @item "MaxIntensity"
+## @itemx "max_intensity"
+## The maximum intensity inside the object.
+## @item "MinIntensity"
+## @itemx "min_intensity"
+## The minimum intensity inside the object.
+## @item "WeightedCentroid"
+## @itemx "weighted_centroid"
+## The centroid of the object where pixel values are used as weights.
+## @item "MeanIntensity"
+## @itemx "mean_intensity"
+## The mean intensity inside the object.
+## @item "PixelValues"
+## @itemx "pixel_values"
+## The pixel values inside the object represented as a vector.
+## @end table
+##
+## The requested properties can either be specified as several input arguments
+## or as a cell array of strings. As a short-hand it is also possible to give
+## the following strings as arguments.
+##
+## @table @t
+## @item "basic"
+## The following properties are computed: @t{"Area"}, @t{"Centroid"} and @t{"BoundingBox"}.
+## @item "all"
+## All properties are computed.
+## @end table
+##
+## If no properties are given, @t{basic} is assumed.
+## @seealso{bwlabel, bwperim, bweuler}
+## @end deftypefn
+
+function retval = regionprops (bw, varargin)
+ ## Check input
+ if (nargin < 1)
+ error ("regionprops: not enough input arguments");
+ endif
+
+ if (!ismatrix (bw) || ndims (bw) != 2)
+ error ("regionprops: first input argument must be a NxM matrix");
+ endif
+
+ if (numel (varargin) == 0)
+ properties = "basic";
+ elseif (numel (varargin) == 1 && iscellstr (varargin {1}))
+ properties = varargin {1};
+ elseif (iscellstr (varargin))
+ properties = varargin;
+ else
+ error ("regionprops: properties must be a cell array of strings");
+ endif
+
+ if (ischar (properties) && strcmpi (properties, "basic"))
+ properties = {"Area", "Centroid", "BoundingBox"};
+ elseif (ischar (properties) && strcmpi (properties, "all"))
+ properties = {"area", "eulernumber", "boundingbox", "extent", "perimeter", ...
+ "centroid", "pixelidxlist", "filledarea", "pixellist", ...
+ "filledimage", "image", "maxintensity", "minintensity", ...
+ "weightedcentroid", "meanintensity", "pixelvalues"};
+ elseif (!iscellstr (properties))
+ error ("%s %s", "regionprops: properties must be specified as a list of",
+ "strings or a cell array of strings");
+ endif
+
+ ## Get a labelled image
+ if (!islogical (bw) && all (bw >= 0) && all (bw == round (bw)))
+ L = bw; # the image was already labelled
+ num_labels = max (L (:));
+ else
+ [L, num_labels] = bwlabel (bw);
+ endif
+
+ ## Compute the properties
+ retval = struct ();
+ for k = 1:numel (properties)
+ switch (lower (properties {k}))
+ case "area"
+ for k = 1:num_labels
+ retval (k).Area = local_area (L == k);
+ endfor
+
+ case {"eulernumber", "euler_number"}
+ for k = 1:num_labels
+ retval (k).EulerNumber = bweuler (L == k);
+ endfor
+
+ case {"boundingbox", "bounding_box"}
+ for k = 1:num_labels
+ retval (k).BoundingBox = local_boundingbox (L == k);
+ endfor
+
+ case "extent"
+ for k = 1:num_labels
+ bb = local_boundingbox (L == k);
+ area = local_area (L == k);
+ retval (k).Extent = area / (bb (3) * bb (4));
+ endfor
+
+ case "perimeter"
+ for k = 1:num_labels
+ retval (k).Perimeter = sum (bwperim (L == k) (:));
+ endfor
+
+ case "centroid"
+ for k = 1:num_labels
+ [Y, X] = find (L == k);
+ retval (k).Centroid = [mean(X), mean(Y)];
+ endfor
+
+ case {"pixelidxlist", "pixel_idx_list"}
+ for k = 1:num_labels
+ retval (k).PixelIdxList = find (L == k);
+ endfor
+
+ case {"filledarea", "filled_area"}
+ for k = 1:num_labels
+ retval (k).FilledArea = sum (bwfill (L == k, "holes") (:));
+ endfor
+
+ case {"pixellist", "pixel_list"}
+ for k = 1:num_labels
+ [Y, X] = find (L == k);
+ retval (k).PixelList = [X, Y];
+ endfor
+
+ case {"filledimage", "filled_image"}
+ for k = 1:num_labels
+ retval (k).FilledImage = bwfill (L == k, "holes");
+ endfor
+
+ case "image"
+ for k = 1:num_labels
+ tmp = (L == k);
+ [R, C] = find (tmp);
+ retval (k).Image = tmp (min (R):max (R), min (C):max (C));
+ endfor
+
+ case {"maxintensity", "max_intensity"}
+ for k = 1:num_labels
+ retval (k).MaxIntensity = max (bw (L == k) (:));
+ endfor
+
+ case {"minintensity", "min_intensity"}
+ for k = 1:num_labels
+ retval (k).MaxIntensity = min (bw (L == k) (:));
+ endfor
+
+ case {"weightedcentroid", "weighted_centroid"}
+ for k = 1:num_labels
+ [Y, X] = find (L == k);
+ vals = bw (L == k) (:);
+ vals /= sum (vals);
+ retval (k).WeightedCentroid = [dot(X, vals), dot(Y, vals)];
+ endfor
+
+ case {"meanintensity", "mean_intensity"}
+ for k = 1:num_labels
+ retval (k).MaxIntensity = mean (bw (L == k) (:));
+ endfor
+
+ case {"pixelvalues", "pixel_values"}
+ for k = 1:num_labels
+ retval (k).PixelValues = bw (L == k)(:);
+ endfor
+
+ case "orientation"
+ for k = 1:num_labels
+ [Y, X] = find (L == k);
+ if (numel (Y) > 1)
+ C = cov ([X(:), Y(:)]);
+ [V, lambda] = eig (C);
+ [max_val, max_idx] = max (diag (lambda));
+ v = V (:, max_idx);
+ retval (k).Orientation = 180 - 180 * atan2 (v (2), v (1)) / pi;
+ else
+ retval (k).Orientation = 0; # XXX: What does the other brand do?
+ endif
+ endfor
+
+ %{
+ case "majoraxislength"
+ for k = 1:num_labels
+ [Y, X] = find (L == k);
+ if (numel (Y) > 1)
+ C = cov ([X(:), Y(:)]);
+ lambda = eig (C);
+ retval (k).MajorAxisLength = (max (lambda));
+ else
+ retval (k).MajorAxisLength = 1;
+ endif
+ endfor
+
+ case "minoraxislength"
+ for k = 1:num_labels
+ [Y, X] = find (L == k);
+ if (numel (Y) > 1)
+ C = cov ([X(:), Y(:)]);
+ lambda = eig (C);
+ retval (k).MinorAxisLength = (min (lambda));
+ else
+ retval (k).MinorAxisLength = 1;
+ endif
+ endfor
+ %}
+
+ #case "extrema"
+ #case "convexarea"
+ #case "convexhull"
+ #case "solidity"
+ #case "conveximage"
+ #case "subarrayidx"
+ #case "eccentricity"
+ #case "equivdiameter"
+
+ otherwise
+ error ("regionprops: unsupported property '%s'", properties {k});
+ endswitch
+ endfor
+endfunction
+
+function retval = local_area (bw)
+ retval = sum (bw (:));
+endfunction
+
+function retval = local_boundingbox (bw)
+ [Y, X] = find (bw);
+ retval = [min(X)-0.5, min(Y)-0.5, max(X)-min(X)+1, max(Y)-min(Y)+1];
+endfunction
+
git://git.creatis.insa-lyon.fr / CreaPhase.git / blobdiff