U.S. Philips Corporation

Stephanus M Borgers

Peter H De With

Egidius A Habraken

Roberto Woudsma

Roeland Pieter De Bruijne

David C Chong

Brian T McSweeney

Cornelis P Visser

In a television transmission system a digital luminance signal Dy and two digital color difference signals DCHR(1) and DCHR(2) are applied to a distribution circuit 3 at the transmitter end, which digital color difference signals are applied thereto possibly after having been subjected to a vertical decimation operation with a decimation factor R. The distribution circuit 3 partitions all these signals into groups of Q sample per group. After receiving an even number of luminance groups and an even number of chrominance groups, a first half of this number of luminance groups and a first half of this number of chrominance groups is applied to a first auxiliary picture signal output 3(4) of the distribution circuit 3, while simultaneously the other half of the number of luminance groups and the other half of the number of chrominance groups is applied to a second auxiliary picture signal output (3(5) of the distribution circuit. A transformer for performing a forward two-dimensional Q*Q transform is connected to each of these auxiliary picture signal outputs.

Television system for digital transmission of picture signals

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).

One-dimensional linear picture transformer

Television system in which digitalized picture signals subjected to a transform coding are transmitted from an encoding station to a decoding station. In a television system a digital picture signal is subjected to a transform coding for the purpose of bit rate reduction. In order to detect motion effects between the two fields of a picture, these fields are also examined in a motion detector 8310. If no motion is detected, intraframe transform is employed and if motion is detected intrafield transform is employed. Small motion effects can be eliminated by subjecting the picture signal to a median filtering before subjecting it to an intraframe transform.

Television system in which digitized picture signals subjected to a

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.

Discrete cosine transform arrangement

A television transmission system for digital picture signals in which each picture is split up into sub-pictures of NxN pixels for the purpose of reducing the bit rate. Each sub-picture is subjected to a two-dimensional discrete cosine transform (DCT) for determining basic picture weighting factors (coefficients) which are converted by adaptive coding into code words of variable length. This two-dimensional DCT is realized by multiplying the pixels of each row of the sub-picture by the NxN DCT matrix (one-dimensional transform). Consequently, an NxN array of product elements is obtained. The transposed version thereof is once more multiplied by the NxN DCT matrix. Such a one-dimensional transform includes three main steps. In a first main step, the pixels of a row are converted in a first iteration step, into N/2 sum elements u.sub.1,i and N/2 difference elements v.sub.1,i. In a subsequent iteration step, the N/2 sum elements u.sub.1,i are converted into N/4 further sum elements u.sub.2,i and N/4 further difference elements v.sub.2,i. This process is repeated until only two sum elements are left. The difference elements obtained in each step are used to determine a plurality of auxiliary sum elements in still further iteration steps. The remaining two sum elements, the difference elements and the auxiliary sum elements are each multiplied in the second main step by an associated linear combination of elements of the DCT matrix. Of the sub-products thus obtained, selected one's of those products are added together or are subtracted from each other in the third main step so that the desired product elements are obtained.

Growing community of inventors

Eindhoven, Netherlands

Stephanus M Borgers