Nec Corporation

Nec Home Electronics, Inc.

Sony Corporation

Yoshihiro Miyamoto

Mutsumi Ohta

Ryoma Oami

Keiichi Chono

Yuzo Senda

Toshio Koga

Junichi Ohki

Hideto Kunhiro

Intended is to obtain a video encoding device, a video encoding method, and a video encoding program which enable to prevent reduction in compression efficiency caused by drastic changes in symbol occurrence probabilities in context adaptive coding, and a video decoding device, a video decoding method and a decoding program corresponding thereto. The video datais input into video encoding device on a macroblock basis, and after quantization, the PCM determination unitdetermines whether the coded datais PCM mode or not. Even when the coded datais PCM mode, the context updating unitexecutes context updating processing so as to improve efficiency of binary arithmetic coding. According to the determination of PCM mode or non PCM mode, the third switchsupplies either binary arithmetic coding output or PCM coding output as its output data.

Video encoding device, video decoding device, video encoding method, video decoding method, video encoding or decoding program

When entropy-encoding a converted quantized amount obtained by converting an image into a frequency region and quantizing it, if the output code bit quantity of the entropy encoding exceeds a predetermined amount, an image obtained by rebuilding the converted quantized value is outputted from an image encoding device. This guarantees an encoding delay caused by re-encoding to be a constant time without increasing the circuit size of the encoding device and provides an image encoding device of a subjectively high quality.

Image encoding method, device using the same, and computer program

Distance from a small block to a synchronizing pattern inserted into coded data is calculated for each small block in an image frame. On the basis of the count, a data-loss probability estimation unit estimates the probability that coded data of a target small block will be lost during transmission. In regard to a small block in which interframe predictive coding has been performed, an image-quality degradation estimation unit estimates the degree of image-quality degradation that will be caused in this small block in the decoded image. The forced refresh priority of each small block is calculated upon comparing the estimated data-loss probability and estimated degree of image-quality degradation with threshold values, and the values of priority are recorded in the form of a forced refresh map. When the next frame is coded, reference is had to the recorded values of priority and a small block in which intraframe coding will be forcibly performed is selected based upon the recorded values of priority. When some coded data is lost owing to the occurrence of an error, therefore, a decline in the quality of the decoded image can be suppressed in an effective manner.

Moving-picture coding apparatus and method

In an image size transformation method for an orthogonal transformation coded image, orthogonal coefficients as coded data of an image are read out by blocks, after which an operation process for transforming the coefficients on the orthogonal coefficients is carried out. Due to this operation process, coefficients of Y blocks are obtained from coefficients of X blocks, by which the orthogonal coefficients after having the image size enlarged or reduced are outputted. Due to this structure, it is possible to simplify the decoding system. According to the image size transformation method of the present invention, orthogonal transformation coefficients are processed directly on the coefficients by which a transformation of high precision is possible, while there is no possibility that a transformation efficiency will deteriorate because of operation errors caused by inversion or filtering, as in the conventional case.

Image size transformation method for orthogonal transformation coded image

The present invention relates to a digital watermark insertion system that automatically calculates a digital watermark strength suitable to an input image and inserts a digital watermark into the image. The image categorizing section classifies input images and outputs category indexes. The storage device stores digital watermark characteristic tables describing the correspondences between digital watermark strength, image-quality degradation degree and attack-resistant evaluation value by category index and selects a digital watermark characteristic table to be used according to an input category index. The digital watermark strength calculation section outputs a digital watermark strength to the storage device, calculates an optimum digital watermark strength using an image-quality degradation degree and a resistant evaluation value output from the storage device and constraint information input by an user. The digital watermark insertion section converts embedded data into a digital watermark and inserts the digital watermark in an input image with the strength of an input optimum digital watermark strength, thus outputting a watermarked image.

Digital watermark insertion system and digital watermark characteristic table creating device

In a coding system, an input picture is split into regions with adaptive configurations to a reference picture, a selected region with precedence data is detected of its configuration and of its relative motion to a corresponding region of the reference picture, a prediction region is generated from the corresponding region of the reference picture and the relative motion, a difference region is determined between the selected region and the prediction region, and the precedence data, detected configuration, relative motion and difference ergion are coded. In a decoding system, a decoded prediction region is generated from a decoded relative motion and a corresponding region of a reference picture selected by a decoded precedence data, and a decoded difference region is added to the decoded prediction region to obtain a decoded picture region, which is configuration-corrected by a decoded configuratrion data, before synthesizing a plurality of decoded picture regions to obtain a synthesized picture region.

System and method for coding and/or decoding image-adaptive split region

System and method for coding and/or decoding image adaptive split region

In a coding system, an input picture is split into regions with adaptive configurations to a reference picture, a selected region with precedence data is detected of its configuration and of its relative motion to a corresponding region of the reference picture, a prediction region is generated from the corresponding region of the reference picture and the relative motion, a difference region is determined between the selected region and the prediction region, and the precedence data, detected configuration, relative motion and difference region are coded. In a decoding system, a decoded prediction region is generated from a decoded relative motion and a corresponding region of a reference picture selected by a decoded precedence data, and a decoded difference region is added to the decoded prediction region to obtain a decoded picture region, which is configuration-corrected by a decoded configuration data, before synthesizing a plurality of decoded picture regions to obtain a synthesized picture region.

In an image processing system for use in processing a sequence of image signals carrying a moving image, the image signal sequence is divided into a sequence of partial image signals each of which carries a scene subsequence defined by scene changes. A background signal generator determines a background portion of the moving image by monitoring a whole of each partial image signal and produces a background signal. The background signal is coded by a coder prior to a sequence of error signals resulting from predictive coding of each partial signal. During prediction of the background signal, the error signals may be rendered to zero in the coder. The background signal may be either determined at every picture element or at every block composed of a plurality of picture elements.

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Tokyo, Japan

Yoshihiro Miyamoto