Patent application number | Description | Published |
20110206110 | Data Compression for Video - A method of compressing video data, the method comprising: providing image data for each of a plurality of image portions; determining an index value for each of said image portions based on the respective image data; for a target image portion to be encoded, identifying a matching image portion having an index value within a search threshold of the index value of the target image portion; and generating difference data for the target image portion relative to the matching image portion, and including the difference data in an encoded video signal. | 08-25-2011 |
20110206113 | Data Compression for Video - A method of transmitting video data from a transmitter to a receiver, the method comprising: receiving data values of a video signal at a higher resolution; at the transmitter, combining groups of the data values into one or more first units of a first lower-resolution arrangement; encoding and transmitting the first lower-resolution arrangement to the receiver; at the transmitter, combining groups of the data values into one or more second units of a second lower-resolution arrangement, wherein the second units are offset from the first units by a fractional shift such that each second unit partially overlaps with at least one first unit; encoding and transmitting the second lower-resolution arrangement to the receiver; and transmitting an indication of said shift to the receiver; and at the receiver, combining the first and second lower-resolution arrangements based on the indication so as to reconstruct an image of at least a higher resolution than that of the first and second lower-resolution arrangements. | 08-25-2011 |
20110206117 | Data Compression for Video - A method of selecting reference blocks for intra or inter prediction coding of a current block of a video signal. Each reference blocks is selected by: (i) determining a group of candidate blocks comprising at least some candidate blocks other than immediately adjacent spatial neighbours of the current block; and (ii) selecting one of the candidate blocks as the reference block based on a second metric, different from the first metric, the second metric relating to a number of bits that would be required in the encoded bitstream to encode both the residual block and the side information identifying the respective reference block. | 08-25-2011 |
20110206118 | Data Compression for Video - The present invention provides an encoded bitstream and corresponding decoder. An encoded bit stream of compressed video data represents a plurality of successive video frames with each frame being divided into a plurality of portions and each portion corresponding to a plurality of pixels. The encoded bit stream comprises: a set of quantized transform domain coefficients representing a first one of said portions; difference data for a second one of said portions, wherein the difference data defines a difference between transform domain coefficients of the first portion and the predicted second portion, such that the second portion can be predicted from the first portion; and an address specifying the location of the first portion in terms of a whole number of said portions instead of a pixel offset. | 08-25-2011 |
20110206119 | Data Compression for Video - A method of compressing a video signal. The method comprises: for each of a plurality of image portions, transforming from a spatial domain representation into a transform domain representation; and for each of a plurality of target image portions to be encoded, determining a respective reference portion, determining a prediction of the target image portion based on the reference portion, and encoding the target image portion based on the prediction. The prediction comprises predicting a non-lateral motion of the target image portion relative to the reference portion based on processing of their transform domain coefficients. The encoding comprises generating an encoded bitstream comprising information about the non-lateral motion for use by a decoder. | 08-25-2011 |
20110206131 | Entropy Encoding - An encoder stage, and corresponding encoded bitstream and decoder. The encoder stage comprises: a variable length encoder for encoding an input signal; and a counter configured to dynamically detect an observed frequency at which different symbols are found to occur within each of a plurality of predetermined portions of the input signal, prior to the symbols of each respective portion being encoded by the variable length encoder. The variable length encoder is configured to encode the symbols of each portion using variable length coding performed in dependence on the observed frequencies detected within the respective portion of the input signal, to generate an encoded bitstream comprising the encoded symbols along with an additional element indicating information regarding the observed frequencies detected for each portion, and to output the encoded bitstream to at least one of a storage medium and a transmission medium for supply to a decoder. | 08-25-2011 |
20110206132 | Data Compression for Video - A method of encoding a video signal for transmission, comprising: receiving a video signal comprising a plurality of video frames, each frame being divided into a plurality of image portions; for each of a plurality of target ones of said image portions to be encoded, selecting a respective reference portion, generating respective residual data based on the target portion relative to the respective reference portion; during ongoing encoding of the video signal, generating a table of commonly usable reference portions and transmitting an indication of the table to a decoder; and generating an encoded bitstream comprising the residual data together with side information identifying the selected reference portions by reference to an entry in said table, and transmitting the encoded bitstream to the decoder. | 08-25-2011 |
20120044990 | Data Compression For Video - The present invention provides a technique for performing one or more aspects of video coding such as quantization, intra prediction coding or inter prediction coding in dependence on a perceptual model taking into account human sensitivity to data in the video signal. The perceptual model may relate to spatial frequency, temporal frequency, contrast sensitivity, colour sensitivity, a structural metric, and/or one or more parameters affecting perception such as motion in the video, the distance of a recipient user from the screen, and the size, aspect ratio or resolution of the screen of the recipient terminal. | 02-23-2012 |
20140105277 | Color Adaptation in Video Coding - A video bitstream is received from an encoder, comprising encoded image portions each having a common form representing components of a channel in a color space. Each of a plurality of the encoded image portions comprises a different set of quantized values of the components, including at least a value of a first of the components being quantized from amongst a first scheme of quantized levels. Further, the received bitstream comprises a look-up table mapping the quantized levels of the first scheme to at least partially de-quantized respective levels. A de-quantizer uses the look-up table received in the bitstream to at least partially de-quantize the different quantized values of the first component in a plurality of the image portions, by converting the quantized values of the first component to at least partially de-quantized values corresponding to ones of the at least partially de-quantized levels of the first scheme. | 04-17-2014 |
20140105278 | COLOR ADAPTATION IN VIDEO CODING - A receiver receives a video bitstream from an encoder, comprising encoded image portions each having a common form representing components of a channel in a color space. Each of a plurality of the encoded image portions comprises a different set of quantized values of the components, including values of one or more first ones of the components quantized according to a first scheme. The received bitstream further comprises, for each of the one or more first components, an indication of one or more characteristic points in a respective quantization level distribution according to the first scheme, but fewer points per distribution than there are quantized levels of the respective distribution. A de-quantizer at least partially de-quantizes the different quantized values of that first component using the points of the respective distribution, by reconstructing the distribution from those points. | 04-17-2014 |
20140118460 | Video Coding - An encoding system comprises: an input for receiving a video signal comprising a plurality of frames each comprising a plurality of higher resolution samples; and a projection generator configured, for each respective one of the frames, to generate multiple different projections of the respective frame. Each projection comprises a plurality of lower resolution samples representing the respective frame at a lower resolution, wherein the lower resolution samples of the different projections represent different but overlapping groups of the higher resolution samples of the respective frame. The encoding system comprises an encoder configured to encode the video signal by encoding the projections of each of the respective frames. | 05-01-2014 |
20140118562 | VIDEO DATA - Computer program products and a mobile terminal for transmitting and receiving video data. Image data of first and second frames of a video signal captured by a camera is used to determine encoded first spatial units of the first frame and encoded second spatial units of the second frame at lower spatial resolution, which are transmitted to the receiver terminal. The second spatial units are unaligned with the first spatial units due to rotation of the camera between the first and second frames, such that each of the second spatial units partially overlaps with at least one first spatial unit. An indication of the angle of rotation of the camera between the first and second frames is detected using a rotational motion sensor and transmitted to the receiver terminal. The receiver terminal combines the first and second spatial units using the indication to reconstruct an image of higher spatial resolution. | 05-01-2014 |
20140119446 | PRESERVING ROUNDING ERRORS IN VIDEO CODING - An input receives a video signal comprising a plurality of frames of a video image, each frame comprising a plurality of higher resolution samples. A projection generator generates a different respective projection of each of a sequence of the frames, each projection comprising a plurality of lower resolution samples, wherein the lower resolution samples of the different projections represent different but overlapping groups of the higher resolution samples which overlap spatially in a plane of the video image. Inter frame prediction coding is performed between the projections of different ones of the frames based on a motion vector for each prediction. The motion vector is scaled down from a higher resolution scale corresponding to the higher resolution samples to a lower resolution scale corresponding to the lower resolution samples. An indication of a rounding error resulting from this scaling is determined and signalled to the receiving terminal. | 05-01-2014 |
20140119456 | ENCODING VIDEO INTO LOWER RESOLUTION STREAMS - A transmitting terminal comprises: an input for receiving a video signal comprising a plurality of frames representing a video image at different respective times, each frame comprising a plurality of higher resolution samples; a projection generator configured to generate multiple different projections of the video image, each projection comprising a plurality of lower resolution samples representing the video image at a lower resolution, wherein the lower resolution samples of the different projections represent different but overlapping groups of the higher resolution samples which overlap spatially in a plane of the video image; an encoder configured to encode the video signal by encoding the different projections into separate respective encoded streams; and a transmitter configured to transmit each of the separate encoded streams to a receiving terminal over a network. | 05-01-2014 |