Estimating overcomplete independent component bases for image windows
Estimating overcomplete ICA bases for image windows is a difficult problem. Most algorithms require the estimation of values of the independent components which leads to computationally heavy procedures. Here we first review the existing methods, and then introduce two new algorithms that estimate an approximate overcomplete basis quite fast in a high-dimensional space. The first algorithm is based on the prior assumption that the basis vectors are randomly distributed in the space, and therefore close to orthogonal. The second replaces the conventional orthogonalization procedure by a transformation of the marginal density to gaussian.
overcomplete basis gaussianization independent component analysis image representation quasi-orthogonality