Accession Number : ADD006133

Title :   Apparatus for Performing a Discrete Cosine Transform of an Input Signal.

Descriptive Note : Patent,


Personal Author(s) : Speiser,Jeffrey M ; Alsup,James M

Report Date : 01 May 1979

Pagination or Media Count : 12

Abstract : This patent discloses apparatus for performing a discrete cosine transform of an input signal, suitable for real-time television image processing, specifically for obtaining an acceptable picture when the number of bits of information available for describing the picture and/or the channel bandwidth are severely limited, comprising: two read-only memories, each containing a predetermined number of +1's and -1's arranged in a predetermined manner; two multipliers, each having an input from one of the read-only memories, and another, joint input connectable to the input signal which is to be transformed discretely and cosinusoidally; two transversal filters, each having N taps, rather than twice the number (2N-1) of taps in the prior art discrete cosine filters, the input to each filter being the output of one of the multipliers; and a single-pole double-throw switch, which switches position at every shift of the samples through the filter, the output of the transform apparatus being connected to the switch arm, each of the free terminals of the switch being connected to the output of one of the transversal filters. (Author)

Descriptors :   *Patents, *Signal processing, *Image processing, Discrete fourier transform, Read only memories, Radiofrequency filters, Electric switches

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE