Methods and devices transform image data, which are transformed by a compression filter before being compressed and stored in a reference image memory. In an extension, an inverse transformation to that of the compression filter is performed by a decompression filter when image data from the reference memory are read out and decompressed. The methods and devices can be used for image compression methods and image decompression methods that use reference image memories.

There are provided methods and apparatus for transform selection in video coding. An apparatus includes a video encoder for encoding at least a block in a picture by selecting a transform to apply to a residue of the block from a set of two or more available transforms. The transform is selected based on at least one of an inter prediction mode used to predict at least one reference for the block, one or more values corresponding to a motion vector, a value of a residue of one or more previously encoded blocks, a value of prediction data for the block, one or more transform selections of one or more neighboring reconstructed blocks, and a quantization step applied to transform coefficients for the residue of the block.

Presented herein is lossless and near-lossless image compression. In one embodiment, there is described a method for encoding data. The method comprises receiving said data; quantizing a predetermined amount of the data with a predetermined quantization step; determining how many bits represent the predetermined amount of the data quantized with the predetermined quantization step; and wherein if the amount of data exceeds a predetermined amount of bits, changing the quantization step.

Provided is a method for encoding parameter sets at slice level. The method includes: when there are one or more parameter sets, in which the coding tool parameters are identical to the coding tool parameters of a part of coding tools used for the current slice, in the existing parameter sets, encoding the identifiers of parameter sets into bit-stream of the current slice, wherein a parameter set contains common information of the coding tools used in the process of encoding/decoding slice(s). Correspondingly, also provided is a method for decoding parameter sets at slice level and a device for encoding and decoding parameter sets at slice level, which can make full use of the encoded parameter set information when the slice header refers to a plurality of parameter sets, implement flexible configuration of the coding tools used in the process of encoding/decoding slice(s) and reduce information redundancy.

A frame processor for preparing a stream of video frames for encoding, the frame processor being arranged to receive a video frame having first pixel dimensions representing the number of pixels along each dimension of the video frame, and comprising: a rescaling filter configured to rescale the received video frame such that one or both of the first pixel dimensions are no greater than respective predetermined pixel dimension(s) and the aspect ratio of the received video frame is maintained; and a frame generator configured to: embed the rescaled video frame within an output video frame having the predetermined pixel dimensions; and mark pixels of the output video frame outside the bounds of the rescaled video frame as inactive; the frame processor being arranged to provide the output video frame to a video encoder.

The present invention includes obtaining block type identification information on a partition of the current macroblock when the current macroblock is intra-mixed, specifying a block type of the current macroblock based on the block type identification information, obtaining an intra prediction mode of the current macroblock according to the block type of the partition of the current macroblock, and predicting the current macroblock using the intra prediction mode and a pixel value of a neighboring block.

An apparatus for monitoring movement of objects of interest in an area includes an activity map generation circuit and a unified activity map generation circuit. The activity map generation circuit is configured to: generate a plurality of activity maps based on video content from a plurality of cameras, each of the plurality of activity maps being indicative of relative activity of the objects of interest over time within a field of view of a camera among the plurality of cameras, and each of the plurality of cameras having a different corresponding field of view in the area; and standardize the plurality of activity maps with regard to a single common point of view. The unified spatial activity map generation circuit is configured to combine the plurality of standardized activity maps into a unified activity map.

A system implements a hybrid coding mode. The hybrid coding mode may implement a transform to decompose an input stream into frequency components. The frequency components may include frequency bands such as those resulting from a wavelet transform. The frequency components may have associated coefficients which may be determined via the transform. The hybrid coding mode may also implement a predictor-based coding mode. A predictor-based coding mode uses a set of values as predictors for another set of values. The hybrid mode may be implemented by using predictor-based coding to code a portion of the coefficients. For example, a coefficient may be used as a predictor for another coefficient of same frequency component. In some implementations, dynamic selection between a hybrid coding mode and a point coding mode may be used.

Disclosed is a method of decoding residual coefficients of a transform unit from a bitstream of video data. The method receives the transform unit (1500) from the bitstream of video data in which the transform unit has upper (1503) and lower (1502) level square layers. The upper level layer represents a square arrangement of at most four significant coefficient group flags with each of the significant coefficient group flags representing a non-overlapping region of the lower level layer. The method determines determining the significant coefficient group flags of the square upper level layer for the received transform unit, and determines values of residual coefficients of the square lower layer according to the determined significant coefficient group flags to decode the transform unit of the bitstream of video data. Corresponding encoding methods are also disclosed.

Video data are coded in a coding-standard layered bit stream. Given a base layer (BL) and one or more enhancement layer (EL) signals, the BL signal is coded into a coded BL stream using a BL encoder which is compliant to a first coding standard. In response to the BL signal and the EL signal, a reference processing unit (RPU) determines RPU processing parameters. In response to the RPU processing parameters and the BL signal, the RPU generates an inter-layer reference signal. Using an EL encoder which is compliant to a second coding standard, the EL signal is coded into a coded EL stream, where the encoding of the EL signal is based at least in part on the inter-layer reference signal. Receivers with an RPU and video decoders compliant to both the first and the second coding standards may decode both the BL and the EL coded streams.