U.S. Philips Corporation

Timothy I Trew

Franciscus W Vreeswijk

Gabriele C Seeling

Jan Van Der Meer

Richard D Gallery

Henk W Begas

An interactive television system includes television transmission apparatus (TTA), a transmission path (TPA) and a plurality of television receivers (TRA-1 to TRA-n). The television receivers include a telephone interface (TRT-1 to TRT-n) by which they can communicate with the television transmission apparatus (TTA). The system is arranged to enable interactive games to be played where viewers compete with contestants in a television studio. For a first portion of the program the viewers compete independently and the television receiver accumulates the score. For the final stages of the program viewers with a score above a transmitted threshold are invited to.

Interactive television game system

A method and apparatus for processing an applied signal. The applied signal is low pass filtered via a low pass filter having an input and an output, wherein the filter input and output are coupled to respective inputs of a selection device and respective inputs of a comparator. The comparator compares each of its inputs to one another and produces an output indicating which of its inputs has a lower amplitude. The comparator output is applied to a control input of the selection device such that the selection device will output the signal with the lower amplitude, either the applied signal or the low pass filtered signal.

Method and apparatus for processing a signal

A method of encoding a sequence of images including a moving object, comprises forming an initial template, extracting a mask outlining the object, dividing the template into a plurality (for example sixteen) sub-templates, searching the next frame to find a match with the template, searching the next frame to find a match with each of the sub-templates, determining the displacements of each of the sub-templates with respect to the template, using the displacements to determine affine transform coefficients and performing an affine transform to produce an updated template and updated mask. Encoding is performed at a higher resolution for portions within the outline than for portions outside the outline.

Method and apparatus for encoding pictures including a moving object

A face classification system which receives video data representative of a scene and extracts therefrom data representative of a face which is present in the scene. The facial video data is applied to a homomorphic filter to eliminate the effects of lighting changes in the scene. The positions of the eyes and mouth are located to form two sub-divisions, one in relation to a first line joining the eyes and the other in relation to a second line perpendicular to the first line and passing through the nose. A feature vector which is representative of the face and is rotation, scaling, translation and grey level intensity invariant is then produced by applying a recursive second order sub-division of moments to the filtered data. Such sub-division of moments is constrained to act first on the sub-divisions formed by the aforesaid lines, thereby reducing the effect of noise. The feature vector may be applied to a classifier which employs multi-layer perception to compare it with stored feature vectors of faces in one or more previous scenes to determine if the faces match. The system may be used, for example, for allowing access to secure areas or to secure computer work stations.

Classifying faces

A method of tracking a moving object in a scene, for example the face of a person in videophone applications, comprises forming an initial template of the face, extracting a mask outlining the face, dividing the template into a plurality (for example sixteen) sub-templates, searching the next frame to find a match with the template, searching the next frame to find a match with each of the sub-templates, determining the displacements of each of the sub-templates with respect to the template, using the displacements to determine affine transform coefficients and performing an affine transform to produce an updated template and updated mask.

Method and apparatus for tracking a moving object

A video signal with pre-emphasis is applied via an input to an HD-MAC encoder, the encoded output being applied over a first path to an input of an adder. The encoded signal is also applied via a decoder and a further path comprising a de-emphasis circuit, a mean value estimator circuit and a pre-emphasis circuit, to an input of a difference circuit. The video signal from the encoder input is also applied to a second input to the difference circuit, via a reference path comprising components which correspond to the de-emphasis circuit, mean value estimator, and pre-emphasis circuit in the further path. The difference in the pre-emphasized mean values obtained from the difference circuit is applied via a shuffler and added to the video signal in the first path.

Method and apparatus for maintaining the mean valves of video signals

A transmitting section of the system according to the invention has transmitting section signal paths for at least three classes of motion, each with a preprocessing circuit (143, 145 and 147) which are provided with means for individually sampling. These sampling means sample in accordance with separate sampling patterns so that each preprocessing circuit (143, 145 or 147) supplies a video signal which is suitable for a display with an optimum distribution of temporal and/or spatial resolution for the associated class of motion. Dependent on the class of motion determined, one of the preprocessing circuits (143, 145 or 147) is coupled to a channel (170). The video signal to be supplied to the channel (170) is therefore a video signal suitable for a display with an optimum distribution of temporal and/or spatial resolution for the given class of motion (FIG. 1A). A high-definition receiving section of the system according to the invention also has at least three receiving section signal paths comprising a postprocessing circuit (43, 45 and 47) which decodes a received video signl in accordance with a method associated with the relevant postprocessing circuit (43, 45 or 47). The correct postprocessing circuit (43, 45 or 47) is selected in accordance with the class of motion, so that in the receiving section of the system according to the invention a display with an increasing spatial resolution can be achieved in the case of a decreasing motion (FIG. 1B).

Method and apparatus for temporally and spatially processing a video

A receiver for a high definition television signal in which the signal prior to transmission is sub-sampled on a block-by-block basis according to the movement has an input (39) which receives the sub-sampled signal which is applied to a shuffler (40) which shuffles the pixels of blocks in a manner which is the inverse to that performed prior to transmission. The correctly positioned pixels are applied to means (43,44,45) for adaptive switched interpolation filtering capable of providing spatial frequency filter responses which approximate those at the transmitter, for sub-sampling blocks of the interpolated picture are sub-sampled but where pixels adjacent but outside a block are sub-sampled with the same structure as that of the block and for non-adaptive switched interpolation filtering for providing spatial frequency filter responses which substantially correspond to those at the transmitter. An output (46) provides the reproduced high definition television signal. A digitally assisted television signal at a further input 41 is used to control the inverse shuffling and the selection of filter responses.

Method and apparatus for processing signals conveyed in sub-sampled form

A receiver for a high-definition television signal, in which the signal prior to transmission is sub-sampled on a segmented basis according to the degree of movement, has an input terminal (1) which receives the sub-sampled signal which is applied to an inverse shuffler (2) which shuffles the pixels of each block in a manner which is the inverse to that performed prior to transmission. The output of shuffler (2) is applied to a first delay arrangement (4) which provides one or more delays of an integral number of fields periods and whose delayed and undelayed outputs are applied to an input field selector (6) to produce a changed sequence of fields to that received. The selector output is applied to a processing arrangement (8) in which the signal of changed field sequence is subjected to spatial interpolation and/or temporal interpolation and the resulting interpolated signal applied to a second delay arrangement (10) providing one or more delays of an integral number of fields periods. The delayed and undelayed outputs of delay arrangement (10) are applied to an output field selector (12) to produce an output in which the original field sequence is restored.

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Horley, United Kingdom

Timothy I Trew