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“Fourier Coding of Images”
by H.C. Andrews
June 1968
The transmission of two dimensional images over large distances from far ranging space probes has become an important factor in space exploratory research. A common requirement for such transmission systems is a large bandwidth, low noise interference communication link for pleasing reception.
Standard communication systems transmit images as they are normally viewed by light sensing devices such as cameras, photo-sensitive emulsions, and the human eye. This dissertation presents the results of investigations into the feasibility of transmitting the Fourier transform of an image rather than the spatial domain representation. The motivations behind the study of image transmission in the Fourier domain are threefold. First, the Fourier transform tends to compact the image energy in the Fourier domain such that large bandwidth reductions can be obtained. Second, noise energy introduced in the Fourier domain tends to spread over the entire retransformed image, and thus becomes less offensive to the eye. Finally, image enhancement can be accomplished by using nonlinear quantization and coding techniques on the Fourier domain.