7 citations · 19 across the 13 of their papers we have counts for
4 papers · 1 filter
GA based robust blind digital watermarking
Víctor Álvarez, José-Andrés Armario, María-Dolores Frau +4
A genetic algorithm based robust blind digital watermarking scheme is presented. Starting from a binary image (the original watermark), a genetic algorithm is performed searching f…
Embedding cocyclic D-optimal designs in cocyclic Hadamard matrices
Víctor Álvarez, José-Andrés Armario, María-Dolores Frau +1
In this paper a method for embedding cocyclic submatrices with ``large'' determinants of orders 2t in certain cocyclic Hadamard matrices of orders 4t is described (t an odd integer…
Searching for partial Hadamard matrices
Víctor Álvarez, José-Andrés Armario, María-Dolores Frau +4
Three algorithms looking for pretty large partial Hadamard matrices are described. Here "large" means that hopefully about a third of a Hadamard matrix (which is the best asymptoti…
The cohomological reduction method for computing n-dimensional cocyclic matrices
Víctor Álvarez, José-Andrés Armario, María-Dolores Frau +1
Provided that a cohomological model for is known, we describe a method for constructing a basis for -cocycles over , from which the whole set of -dimensional -cocyc…