We describe an algorithm that associates to each positive real number ε and each finite collection Cε of planar pixels of size ε a planar piecewise linear set Sε with the following property: If Cε is the collection of pixels of size ε that touch a given compact semialgebraic set S, then the normal cycle of Sε converges in the sense of currents to the normal cycle of S. In particular, in the limit we can recover the homotopy type of S and its geometric invariants such as area, perimeter and curvature measures. At its core, this algorithm is a discretization of stratified Morse theory.
Keywords: semialgebraic sets, pixelations, normal cycle, total curvature, Morse theory
Nicolaescu, Liviu  1 ; Rowekamp, Brandon  2
@article{10_2140_agt_2014_14_3345,
author = {Nicolaescu, Liviu and Rowekamp, Brandon},
title = {Pixelations of planar semialgebraic sets and shape recognition},
journal = {Algebraic and Geometric Topology},
pages = {3345--3394},
year = {2014},
volume = {14},
number = {6},
doi = {10.2140/agt.2014.14.3345},
url = {http://geodesic.mathdoc.fr/articles/10.2140/agt.2014.14.3345/}
}
TY - JOUR AU - Nicolaescu, Liviu AU - Rowekamp, Brandon TI - Pixelations of planar semialgebraic sets and shape recognition JO - Algebraic and Geometric Topology PY - 2014 SP - 3345 EP - 3394 VL - 14 IS - 6 UR - http://geodesic.mathdoc.fr/articles/10.2140/agt.2014.14.3345/ DO - 10.2140/agt.2014.14.3345 ID - 10_2140_agt_2014_14_3345 ER -
%0 Journal Article %A Nicolaescu, Liviu %A Rowekamp, Brandon %T Pixelations of planar semialgebraic sets and shape recognition %J Algebraic and Geometric Topology %D 2014 %P 3345-3394 %V 14 %N 6 %U http://geodesic.mathdoc.fr/articles/10.2140/agt.2014.14.3345/ %R 10.2140/agt.2014.14.3345 %F 10_2140_agt_2014_14_3345
Nicolaescu, Liviu; Rowekamp, Brandon. Pixelations of planar semialgebraic sets and shape recognition. Algebraic and Geometric Topology, Tome 14 (2014) no. 6, pp. 3345-3394. doi: 10.2140/agt.2014.14.3345
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