Nonuniform image representation in area-of-interest systems

This paper is concerned with image representation by data distributed nonuniformly and in particular with a representation scheme suitable for "area-of-interest" imaging. The class of signals under consideration, whose information density varies with position, can be represented according to a nonuniform sampling scheme. Position-varying projection operators are presented as simple low-pass filtering operations in a Fourier-like domain. Sequential projections are used for pyramidal representation of nonuniformly sampled images. It is shown that irregular random sampling, prevents, under certain mild restrictions, aliasing effects.