Mitsubishi Electric Corporation

Shigeo Ando

Kyosuke Yoshimoto

Kiyoyasu Maruyama

Chihiro Morita

Mitsunobu Yoshinaga

Aki Kimura

Yasuo Maeda

Satoshi Minami

Maki Yukawa

Kosuke Yagi

Kanae Ikeda

Provided is a gateway device for interconnecting an IEEE1394 network and an IP network, which automatically detects and operates an AV device connected to the IEEE1394 network from a player device connected to the IP network, thereby enabling the player device to watch and hear contents stored in the AV device. The gateway device interconnects a network, to which an AV/C installed IEEE1394 device is connected, and a network, to which a player device compliant with a UPnP is connected, and includes: a conversion unit for converting Plug-and-Play processing of the IEEE1394 device to each step of Plug-and-Play of the UPnP; a conversion unit for converting an action of a UPnP AV to an AV/C command of the IEEE1394 device; and a stream transfer unit for transferring stream data transmitted from the IEEE1394 device to the IP network.

Gateway device

Image feature values Va and Vb are derived from image data, coefficients C and D are determined based on the image feature values Va and Vb, and an approximate expression expressed with the file size Sfj of the JPEG compression file and the quantization data coefficient value Aqt is derived. Next, by designating the file size of a desired predetermined JPEG compression file based on the approximate expression, the quantization data coefficient value Aqt is derived, and a first quantization table as a reference is multiplied by the quantization data coefficient value Aqt, whereby a second quantization table is obtained. Then, using the second quantization table, the image data is actually JPEG-compressed.

Jpeg-compressed file creating method

Growing community of inventors

Tokyo, Japan

Shigeo Ando