Tight frames, partial isometries, and signal reconstruction

Abstract

This article gives a procedure to convert a frame which is not a tight frame into a Parseval frame for the same space, with the requirement that each element in the resulting Parseval frame can be explicitly written as a linear combination of the elements in the original frame. Several examples are considered, such as a Fourier frame on a spiral. The procedure can be applied to the construction of Parseval frames for the space of square integrable functions whose domain is the ball of radius When a finite number of measurements is used to reconstruct a signal in error estimates arising from such approximation are discussed.