Sharp Kabushiki Kaisha Corporation

Nippon Telegraph and Telephone Corporation

Takeshi Makiyama

Seiji Sato

Tadashi Uchiumi

Noritaka Koizumi

Osamu Nakamura

Keiichi Hibi

Tsuneaki Iwano

Takashi Oshima

Hirotaka Nakano

Masahiro Shioi

Tsuneko Kura

Jiro Nakabayashi

Youji Kanada

Yoshihiro Nakagawa

A coding and decoding apparatus is constructed so that the coding side transmits coded data together with identifying information for identifying the device of decoding the coded data, and the decoding side is capable of storing a number of decoding schemes so as to perform decoding based on one of the previously stored schemes. The apparatus further has devices for storing the received tools and tool-correspondent information which numerically represents the capacities of the tools so that it can make a comparison between the decoding capacity and the processing capacities of the tools to determine the possibility of the operations of the received tools. Further, a set of the tools are hierarchized so that the coded data produced by the n-ranked tool can be decoded by the (n+1)-ranked tool. Alternatively, the tools are defined in a hierarchical manner so that the decoding tools installed in the decoding apparatus will be able to assure the minimum quality and the requested decoding process can be performed by the received decoding tool. Further, the identification code of the decoding scheme used can be transmitted as required so that the decoding scheme can be expanded by transmitting the differential information from the basic decoding scheme.

Decoding apparatus using tool information for constructing a decoding algorithm

A coding and decoding apparatus is constructed so that the coding side transmits coded data together with identifying information for identifying the device of decoding the coded data, and the decoding side is capable of storing a number of decoding schemes so as to perform decoding based on one of the previously stored schemes. The apparatus further has devices for storing the received tools and tool-correspondent information which numerically represents the capacities of the tools so that it can make a comparison between the decoding capacity and the processing capacities of the tools to determine the possibility of the operations of the received tools. Further, a set of the tools are hierarchized so that the coded data produced by the n-ranked tool can be decoded by the (n&plus;1)-ranked tool. Alternatively, the tools are defined in a hierarchical manner so that the decoding tools installed in the decoding apparatus will be able to assure the minimum quality and the requested decoding process can be performed by the received decoding tool. Further, the identification code of the decoding scheme used can be transmitted as required so that the decoding scheme can be expanded by transmitting the differential information from the basic decoding scheme.

Coding and decoding apparatus which transmits and receives tool

If received coded video-data includes data with an error unable to be decoded or data disagreeing with ITU-T recommendation H.261 (e.g., the number of bits per frame exceeds the limit defined by the recommendation), it must be stored with due countermeasures taken against error and inadaptable data, which allows the stored data to be effectively reproduced. Received coded video-data is decoded by a transmission-line decoding portion and divided into frames by a data dividing portion. Thereafter it is decoded by an information-source decoding portion and then intraframely encoded by a intraframe coding portion. According to a signal from a bit-counting portion showing that the number of bits in one frame of coded video-data exceeds the limit defined by ITU-T recommendation H.261 or anomalous signal of a frame image decoded by the information source decoding portion, a frame-processing control portion decides how to store each frame and controls a storable data transfer portion to select intraframe-coded data and transfer the selected data to a data storage.

Video data storing device and method for coding video data based upon

Communication between an image-information storage device and a terminal is made possible even in a case where they have images of different image formats. An image data delivery request, transmitted from any of a plurality of terminals and received by a receiving portion, includes information indicating that the terminal has a source format of CIF or QCIF. This information is transferred to a communication control portion which informs the source format control portion of the source format (CIF or QCIF of) the terminal. When the terminal has the CIF source format, the required data transmitted from an image-information storage device are transmitted through a transmitter portion to the terminal. When the terminal has the QCIF source format, a part of the image data transferred from the image-information storage device is extracted and converted into data of QCIF format by the source format control portion. The converted data of QCIF source format are then transmitted through a transmitting portion to the terminal.

Image-information format control device for controlling transmission of

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Higashihiroshima, Japan

Takeshi Makiyama