Methods and apparatus are provided for determining quantization parameter predictors from a plurality of neighboring quantization parameters. An apparatus includes an encoder for encoding image data for at least a portion of a picture using a quantization parameter predictor for a current quantization parameter to be applied to the image data. The quantization parameter predictor is determined using multiple quantization parameters from previously coded neighboring portions. A difference between the current quantization parameter and the quantization parameter predictor is encoded for signaling to a corresponding decoder.

Methods, systems, and computer readable media for compressing video images are disclosed. According to one exemplary method, the method includes classifying image pixels in each video image of a series of video images as either foreground or background. The method also includes replacing each pixel classified as background with a time-averaged value of pixel intensity for that pixel. The method further includes compressing the video images using a compression algorithm.

A method and apparatus for adaptively processing video samples in a video signal frame, the video samples being arranged in a Largest Coding Unit. The method comprises extracting a plurality of video samples from the Largest Coding Unit, calculating a correction offset for a first video sample of the extracted plurality of video samples upon the basis of a first value of the first video sample and a second value of a second video sample of the extracted plurality of video samples, and weighting the first video sample with the correction offset.

An intra prediction mode encoding and decoding method, an image decoding device, and an image encoding device operate by deriving most probable modes (MPMs) from surrounding prediction units adjacent to a current prediction unit and deriving an intra prediction mode of the current prediction unit on the basis of an MPM flag indicating whether an MPM having the same prediction mode as the intra prediction mode of the current prediction unit exists among the derived MPMs.

Disclosed is a motion vector smoothing method. The motion vector smoothing method includes acquiring motion vectors of at least one block of a current image by using a reference image, acquiring a candidate motion vector of a current block, based on a motion vector of the current block, and at least one motion vector of at least one block adjacent to the current block, determining a threshold value of the current block according to gradient values of pixels included in the current block, and determining the motion vector of the current block according to the threshold value.

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.

The present invention relates to a method for encoding and decoding a quantized matrix and an apparatus using same, the method for encoding a quantized matrix according to the present invention comprising the steps of: determining a quantization matrix to be used for quantization and quantizing; determining the prediction method used for the quantization of the quantization matrix; and encoding quantization matrix information on the basis of the determined prediction method, wherein the prediction method can be either a prediction method between coefficients in the quantization matrix or a duplicate of the quantization matrix.

When the signal format of a color image is YUV4:2:2, and an intra prediction parameter, which is used for an intra-frame prediction process on the chrominance signals in a prediction block, shows the same prediction mode as an intra prediction mode for the luminance signal in the prediction block, an intra prediction unit 4 converts an index indicating the intra prediction mode for the luminance signal, and performs the intra-frame prediction process on the chrominance signals in an intra prediction mode indicated by the index after conversion.

There are provided an encoding or decoding technique capable of performing more efficient encoding or decoding than before. An encoding apparatus for encoding a time-series signal in a frequency domain is provided with: a spectral envelope estimating portion 2A estimating a spectral envelope, regarding absolute values of a frequency domain sample sequence corresponding to the time-series signal raised to the power of η as a power spectrum, on the assumption that η is a predetermined positive number other than 2; and an encoding portion 2B performing such encoding that changes bit allocation or that bit allocation substantially changes, for each coefficient of the frequency domain sample sequence corresponding to the time-series signal, based on the estimated spectral envelope.

In one embodiment, a method of video encoding, the method comprising: encoding a position of a last non-zero coefficient within a video block, wherein the position of the last non-zero coefficient is provided in a significance map according to block width; and assigning at least one context model to the significance map; wherein the at least one context model includes at least three first contexts, and wherein each of the first three contexts is configured to be shared across two or more blocks of different widths.