SOFSEM
SOFSEM 2001
28th Annual Conference on Current Trends in
Theory and Practice of Informatics
November 24 - December 1, 2001
Piestany, Slovak Republic, Europe

Abstract of Paper

The Reconstruction of Polyominoes from Approximately Orthogonal Projections
by Maciej Gebala

Abstract:

The reconstruction of discrete two-dimensional pictures from their projection
is one of the central problems in the areas of medical diagnostics, 
computer-aided tomography, pattern recognition, image processing and data 
compression. In this note, we determine the computational complexity of the 
problem of reconstruction of polyominoes from their approximately orthogonal 
projections. We will prove that it is NP-complete if we reconstruct 
polyominoes without any restriction, horizontal convex polyominoes and 
vertical convex polyominoes. Moreover we will give the polynomial algorithm 
for the reconstruction of hv-convex polyominoes that has $O(m^3 n^3)$ 
complexity.