The Discrete Frequency Fourier Transform

In certain signal processing applications it may be required to reconstruct a spatial domain image form samples of its Fourier transform. For problems such as this it may be useful to use the dual of the well-known discrete time Fourier transform (DTFT) for purposes of analysis and design. In this paper, this dual concept, called the discrete frequency Fourier transform (DFFT), is shown to be a useful transform in its own right. In addition to being useful for certain physical problems, the DFFT fills a gap in the theory and aids the designer in understanding problems which have inherently sampled frequency domains.