One-dimensional linear picture transformer

Abstract

A one-dimension transformer for use in Transform Picture Coding converts each of a series of N input words into a series of N product words by multiplying this series and a transform matrix of N.times.N transform elements. This transformer has a main input connection bus (14.22) which receives the series of input words, a main output connection bus (14.29) at which the desired N product words occur successively and furthermore three data connection buses (14.23; 14.24; 14.25). For performing the required mathematical operations three circuits are provided; two combination circuits (14.30 and 14.31) for adding or subtracting data words applied thereto to generate result words at their outputs and a multiplier circuit 14.32 for multiplying a data word applied thereto by a mulitplication factor which is related to the transform elements to generate an auxiliary product word at its output. The associated output of each of these three circuits is connected to a different one of the three data connection buses. Furthermore a set of switches SW is associated with each of these three circuits, which switches are controlled in such a way that the input of the relevant circuit can be connected at any instant to at most one of the connection buses which are not connected to the output of the relevant circuit. The main output connection bus (14.29) is selectively connectable at any instant to at most one of the data connection buses (14.23; 14.24; 14.25) by means of a further set of switches (SW10, SW11, SW12).