Abstract: An image processing apparatus in which output pixels of an output image are generated from one or more input images using motion vectors having a sub-pixel accuracy. A motion vector allocator allocates motion vectors in the pixels, and compares a current output pixel with test image areas pointed to by motion vectors in the pixels to detect a most suitable motion vector for the current output pixel. A pixel generator operates in a first mode if the output pixel is within a threshold displacement from an image region having substantially different motion characteristics to those of that output pixel, and in a second mode otherwise. The pixel generator includes a spatial filter generating an output pixel value at a required pixel position to a sub-pixel accuracy.

Abstract: A method of processing successive images of a video signal to generate a representative color value indicative of a representative color of an image sub-area. The method includes detecting a color property of the image sub-area in a current image, generating a filtered color property in respect of the current image by combining a color property for the current image with a filtered color property derived in respect of a corresponding sub-area of a previous image, and deriving the representative color value in dependence on a difference between the color property of the sub-area of the current image and the filtered color property.

Abstract: A video data processing apparatus, that processes video data including a sequence of images, the apparatus including: an object tracker unit configured to detect a presence of one or more objects within an image and to track a detected object across successive images; an identity association unit configured to associate an identity with an object tracked by the object tracker unit; a counter unit configured to, for a first and second identity, count a number of images within which a tracked object associated with the first identity and a tracked object associated with the second identity have both been detected; and a similarity detector unit configured to determine whether two tracked objects are similar in appearance.

Abstract: An image processing method for selecting a subset of n (where n is two or more) images representative of a test set of images. The method includes detecting a degree of similarity between images in the test set of images so that the subset of images comprises those n images having substantially the lowest similarity with other images in the set.

Abstract: Image object detection apparatus in which test regions of a test image are compared with an image property model, a mask defining a subset of pixel positions within a test region, comprises means for comparing pixel properties in the test image defined by the test regions with the image property model to detect a property difference between the image property model and a test region; so that pixel property differences within the mask and pixel property differences outside the mask are combined with opposite respective polarities to form a difference value in respect of that test region, an object being detected in the test image at a test region corresponding to a lowest difference value between the image property model and pixels defined by the test region.

Abstract: A data compression apparatus for performing data compression on input data comprises a quantisation parameter estimation arrangement for deriving an estimated value of a quantisation parameter used in a previous compression/decompression cycle applied to the input data, by detecting rounding effects in data values of at least a subset of the input data; and a parameter selection arrangement, responsive to the quantisation parameter estimation arrangement for selecting a quantisation parameter for use in compression of the input data.

Abstract: Object detection apparatus for detecting objects in a test image comprises means for comparing blocks of a test window of the image with reference data indicative of the presence of an object to generate index figures indicative of a degree of similarity between a region and the reference data; means for storing probability data corresponding to possible values of the index figure and the block position; means operable, in respect of a current block, for accessing a probability value from the storing means in dependence on that block's position within the test window and the index figure generated in respect of that block; and means for combining the probability values corresponding to blocks in a test window to generate a result indicative of the probability of that test window containing an object; in which the probability values in the storing means are ordered by block position then by index figure.

Abstract: A video processing apparatus generates an output frame from two or more input images by deriving pixels to interleave between lines of pixels of a base field. The pixels are derived from one of: a first pixel generator generating a pixel value from one or more fields other than the base field, dependent on a respective motion vector having a sub-pixel resolution; or a second pixel generator generating a pixel value from other pixels of the base field. A spatial phase-correcting filter receives an input group of derived pixels including a current derived pixel, and generates an output phase-corrected current pixel value. A pre-compensation mechanism, operable if a pixel forming part of the derived pixels group has been generated by the second pixel generator, applies spatial phase alteration to approximate the phase of that pixel to the phase of the current derived pixel.

Abstract: A video processing apparatus in which at least a subset of output pixels of an output image are generated from one or more input images using motion vectors having a sub-pixel accuracy. A band filter derives lower and higher spatial frequency portions from the one or more input images. A lower frequency contribution relating to a pixel position nearest a required output pixel position from the lower spatial frequency portion is derived using a respective motion vector. A higher frequency contribution from the higher spatial frequency portion is derived using the respective motion vector. A spatial filter generates, from one or more of the higher frequency contributions, a higher frequency pixel value at the required pixel position. A combiner combines the lower frequency contribution and the higher frequency pixel value to generate an output pixel value relating to the required pixel position.

Abstract: A system and associated methodology of detecting objects using multiple sets of object probability data relating to different respective expected object sizes relative to the image size. A list of locations in an image where an object has been detected is stored, the list defining a probability data set and a probability value for each detected object. Object locations in a set of object probability data as locations at which a local maximum probability value exceeds a threshold probability value are detected and, if that location is substantially similar to a location previously stored in the list, where the local maximum probability value exceeds that relating to the previously stored location. The storing is repeated successively in respect of each set of probability data.

Abstract: A video motion detection apparatus including a mechanism to apply a motion test to detect inter-image motion between two or more test images, the motion test providing a test result providing a motion vector and an indication of the integrity of the detected motion vector, and a mechanism to apply the motion test to one of the test images, to detect intra-image similarity within that test image. The motion vector generated by the inter-image motion test is made available as an output of the apparatus if its associated test result indicates a greater integrity than the test result obtained by the intra-image similarity test, and the motion vector generated by the inter-image motion test is not made available as an output of the apparatus if its associated test result does not indicate a greater integrity than the test result obtained by the intra-image similarity test.

Abstract: A video motion detection apparatus generating successive output video signal messages based on input video signal images. The apparatus applies a motion test detecting inter-image motion between two or more input video signal images, providing two sets of one or more motion vectors used for generating respective output image generating test output images using the respective motion vector sets, and compares image areas in the test output images pointed to by the motion vectors in one or both sets. For a motion vector with less than a predetermined degree of similarity between the image areas, the image areas are divided into two or more smaller image areas and the comparison is applied to each of the smaller areas. The use of motion vectors is inhibited for image areas in the test output images that have less than a predetermined degree of similarity at the image area sizes tested.

Abstract: A video motion detection apparatus includes a mechanism applying a motion test by comparing test areas of an image with respective sets of candidate areas in that or another image and generating motion vectors in dependence on a displacement between each test area and a candidate area giving a greatest similarity between the test area and that candidate area; and a mechanism applying an integrity test to test the motion vectors. For a motion vector failing the integrity test, the corresponding test area is divided into two or more smaller test areas and the motion test is applied again in respect of the two or more smaller areas, and a motion vector passing the integrity test is made available as an output of the apparatus.

Abstract: An image processing apparatus in which output pixels of an output image are generated from one or more input images using motion vectors having a sub-pixel accuracy. A motion vector allocator allocates motion vectors in the set to pixels of the output image, and is configured to compare a current output pixel with test image areas pointed to by motion vectors in the set to detect a most suitable motion vector for the current output pixel. The motion vector allocator includes a spatial filter comparing the current output pixel and a test image area to a sub-pixel accuracy. A pixel generator generates the output pixels, and includes a spatial filter generating an output pixel value at a required pixel position to a sub-pixel accuracy. The spatial filter of the motion vector allocator has fewer filter taps than the spatial filter of the pixel generator.

Abstract: An image processing apparatus in which output pixels of an output image are generated from one or more input images using motion vectors having a sub-pixel accuracy. A motion vector allocator allocates motion vectors in the pixels, and compares a current output pixel with test image areas pointed to by motion vectors in the pixels to detect a most suitable motion vector for the current output pixel. A pixel generator operates in a first mode if the output pixel is within a threshold displacement from an image region having substantially different motion characteristics to those of that output pixel, and in a second mode otherwise. The pixel generator includes a spatial filter generating an output pixel value at a required pixel position to a sub-pixel accuracy.

Abstract: A method of comparing a test image with a set of reference images. The method: divides the test image into one or more test regions; for each test region, compares the test region with one or more reference regions in one or more reference images and identifies the reference region that most closely corresponds to the test region; and generates a comparison value from the comparisons of the test regions with their correspondingly identified reference regions.

Abstract: A method of object detection in video images comprises the steps of: detecting the size and image position of a first object part in two or more images; detecting attributes of a second object part, the second object part being defined by a predetermined orientation and size defined with respect to the size and position of the first object part; and comparing the detected attributes of the second object part in the two or more images detected to contain the first object part; in which the likelihood that the two or more images contain the same object is dependent at least on the comparison of the detected attributes of the second object part in those images.

Abstract: A method of processing successive images of a video signal to generate a representative color value indicative of a representative color of an image sub-area, the method comprises the steps of: (i) detecting a color property of the image sub-area in a current image; (ii) generating a filtered color property in respect of the current image by combining a color property for the current image with a filtered color property derived in respect of a corresponding sub-area of a previous image; and (iii) deriving the representative color value in dependence on a difference between the color property of the sub-area of the current image and the filtered color property.

Abstract: A face detection apparatus for tracking a detected face between images in a video sequence comprises: a first face detector for detecting the presence of face(s) in the images; a second face detector for detecting the presence of face(s) in the images; the first face detector having a higher detection threshold than the second face detector, so that the second face detector is more likely to detect a face in an region in which the first face detector has not detected a face; and a face position predictor for predicting a face position in a next image in a test order of the video sequence on the basis of a detected face position in one or more previous images in the test order of the video sequence; in which: if the first face detector detects a face within a predetermined threshold image distance of the predicted face position, the face position predictor uses the detected position to produce a next position prediction; if the first face detector fails to detect a face within a predetermined threshold image d

Abstract: Video data processing apparatus, the video data comprising a sequence of images comprises: an object tracker operable to detect the presence of one or more objects within an image and to track a detected object across successive images; an identity associator operable to associate an identity with an object tracked by the object tracker; a counter operable, for a first and second identity, to count the number of images within which a tracked object associated with the first identity and a tracked object associated with the second identity have both been detected; and a similarity detector operable to determine whether two tracked objects are similar in appearance; the identity associator being operable to change the identity associated with a first tracked object to the identity associated with a second tracked object if: (a) the similarity detector determines that the first and second tracked objects are similar in appearance and (b) the count corresponding to the identities associated with the first and sec