EP0245903A1
Expired / Lapsed
EP
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Discrete cosine transform arrangement
Assignee: Koninklijke Philips NV
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Filing: 1987-05-06
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Granted: —
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Expires: 2007-05-06
Abstract
Abstract In a 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.
Inventors
- 👤 Stephanus M. C. Borgers
- 👤 Cornelis P. Visser
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 18:36
CPC Classifications
H; H04; H04N; H04N11/00; H04N11/04; G; G06; G06F; G06F17/00; G06F17/10; G06F17/14; G06F17/147
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
151 words
An arrangement for real-time calculation of the discrete cosine transformation coefficients of a group of N signal samples of a time-discrete input signal, comprising: - combination means receiving the signal samples as well as a number of auxiliary samples and adapted to add and subtract predetermined combinations of said samples for generating sum and difference samples; - selection means receiving the sum and difference samples and supplying said auxiliary samples as well as transfer samples, the auxiliary samples being constituted by selected ones of the sum and difference samples and the transfer samples being constituted by the remaining sum and difference samples; - multiplication means receiving the transfer samples and multiplying each by only one weighting factor selected from a plurality of predetermined weighting factors for generating product samples; and - accumulator means receiving the product samples and adapted to accumulate given samples of these product samples for generating the coefficients.
Claim 2
Dependent Claim
151 words
An arrangement for real-time calculation of the discrete cosine transformation coefficients of a group of N signal samples of a time-discrete input signal, comprising: - combination means receiving the signal samples as well as a number of auxiliary samples and adapted to add and subtract predetermined combinations of said samples for generating sum and difference samples; - selection means receiving the sum and difference samples and supplying said auxiliary samples as well as transfer samples, the auxiliary samples being constituted by selected ones of the sum and difference samples and the transfer samples being constituted by the remaining sum and difference samples; - multiplication means receiving the transfer samples and multiplying each by only one weighting factor selected from a plurality of predetermined weighting factors for generating product samples; and - accumulator means receiving the product samples and adapted to accumulate given samples of these product samples for generating the coefficients.
Claim 3
Dependent Claim
157 words
An arrangement for real-time calculation of the N inverse discrete cosine transformation signal samples of a time-discrete signal from a group of N discrete cosine transformation coefficients, comprising - multiplication means receiving the coefficients and multiplying each by only one weighting factor selected from a plurality of predetermined weighting factors for generating product samples; - accumulator means receiving the product samples and adapted to add each time given samples of these product samples together for generating accumulation samples; - combination means receiving the accumulation samples as well as a number of auxiliary samples and adapted to add and subtract predetermined combinations of the said samples for generating sum and difference samples; and - selection means receiving the sum and difference samples and supplying said auxiliary samples as well as transfer samples, the auxiliary samples being constituted selected ones of the sum and difference samples and the transfer samples being constituted by the remaining sum and difference samples.
Claim 4
Dependent Claim
157 words
An arrangement for real-time calculation of the N inverse discrete cosine transformation signal samples of a time-discrete signal from a group of N discrete cosine transformation coefficients, comprising - multiplication means receiving the coefficients and multiplying each by only one weighting factor selected from a plurality of predetermined weighting factors for generating product samples; - accumulator means receiving the product samples and adapted to add each time given samples of these product samples together for generating accumulation samples; - combination means receiving the accumulation samples as well as a number of auxiliary samples and adapted to add and subtract predetermined combinations of the said samples for generating sum and difference samples; and - selection means receiving the sum and difference samples and supplying said auxiliary samples as well as transfer samples, the auxiliary samples being constituted selected ones of the sum and difference samples and the transfer samples being constituted by the remaining sum and difference samples.
Claim 5
Dependent Claim
16 words
An arrangement as claimed in Claim 1, wherein the auxiliary samples are constituted by sum samples.
Claim 6
Dependent Claim
53 words
An arrangement as claimed in Claim 1 or 2 further comprising shuffle means to which the N-signal samples or the N-coefficients are applied in a first sequence and which supplies these signal samples or coefficients in a second sequence which corresponds to the combinations of samples to be added or to be subtracted.
Claim 7
Dependent Claim
61 words
An arrangement as claimed in Claim 1 or 2 wherein the combination means comprises two memories for storing a first and a subsequent second sample, which samples are applied to an adder-subtractor circuit and are supplied by a selection circuit which receives signal samples or the accumulation samples and the auxiliary samples and which applies them selectively to the two memories.
References Cited (Backward Citations)
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