U.S. Philips Corporation

Cornelis P Visser

Stephanus M Borgers

In a discrete cosine transformation (DCT) arrangement with an equivalent distribution between accuracy of intermediate results and the number of calculation operations to be performed, the group of N input samples is first subjected to a shuffle operation (903). Consequently, these input samples are applied to a combination circuit (90) in a sequence which is different from the sequence in which they are received. The combination circuit (90) supplies the sum and the difference of each two successive input samples. A selection circuit (91) continuously returns all sum samples except the last one to the input of the combination circuit. Each difference sample and the last sum sample is multiplied once in a multiplier (92) by one weighting factor from a group of weighting factors and the product samples obtained thereby are group-wise accumulated in an accumulator circuit (93), with each group supplying a transform coefficient.

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Eindoven, Netherlands

Cornelis P Visser