This is a MATLAB/OCTAVE prototype implementation for the paper (CAIP 2017 conference):
"Labeling color 2D digital images in theoretical near logarithmic time"
BY F. Diaz-del-Rio, P. Real, and D. Onchis
Abstract. A design of a parallel algorithm for labeling color
at zones (precisely, 4-connected components) of a gray-level or color 2D digital
image is given. The technique is based in the construction of a particular
Homological Spanning Forest (HSF) structure for encoding topological
information of any image. HSF is a pair of rooted trees connecting the im-
age elements at inter-pixel level without redundancy. In order to achieve
a correct color zone labeling, our proposal here is to correctly building a
sub-HSF structure for each image connected component, modifying an
initial HSF of the whole image. For validating the correctness of our al-
gorithm, an implementation in OCTAVE/MATLAB is written and its
results are checked. Several kinds of images are tested to compute the
number of iterations in which the theoretical computing time differs from
the logarithm of the width plus the height of an image. In general, using
our method it is predicted that real images are to be computed faster
than random images.
1. Open the itp_PRL1_reading_I.m and define a synthetic or real image to be processed
2. Execute itpdef2_main.m
3. If a plot of the MrSF and HSF is needed, set the values to a different to zero value:
plotting_fig = 0;
NOTE: do not do this when working with big images: the plotting consumes a lot of time.
Fernando Diaz-del-Rio (2020). "Labeling color 2D digital images in theoretical near logarithmic time" (https://www.mathworks.com/matlabcentral/fileexchange/62644-labeling-color-2d-digital-images-in-theoretical-near-logarithmic-time), MATLAB Central File Exchange. Retrieved .