Matsushita Electric Industrial Co., Ltd.

Osamu Hirota

Masaki Sohma

Hitoshi Kato

Akino Inoue

Satoshi Kageyu

Shigeru Ando

Shugo Horikami

Shinji Nojima

Yasuharu Shimizu

Michihiro Kobayakawa

Kenji Nagao

A method and system for distributing a key is provided which make use of effects of noise caused at the time of transmitting or receiving a signal to send a key. A transmission signal is amplified at a plurality of stages while the relationship between the transmission signal and noise is being maintained at a level enough to satisfy predetermined criteria for security measures against eavesdropping activities, and the key is sent over a long distance. The aforementioned operation makes it possible to transmit or distribute a key over a long distance while maintaining the relationship between the transmission signal and noise at a level enough to satisfy the criteria for security measures against eavesdropping activities.

System and method for distributing key

A picture transmission system capable of establishing arbitrary picture connections with picture inputting units exceeding in number channel resources of a transmission medium for multiplexing and transmitting video information taken through the picture inputting units. A picture sending state storage unit provided corresponding to each of the picture inputting units virtually retains channel resources whose number equals the number of picture outputting units to which the picture inputting units are in connection. For picture connection switching from one picture outputting unit to a different picture inputting unit, the picture sending state storage unit gives its channel resource to the different picture inputting unit. The system is provided with a picture connection managing unit for controlling the picture connections between the picture inputting units and the picture outputting units. The picture connection managing unit accepts a picture connection request to perform the centralized management of channel resources of the transmission medium to allow dynamic channel resource allocation. Under control of the picture connection managing unit, the picture connection between the picture inputting unit and the picture outputting unit takes place through an allocated channel resource.

Picture transmission system

A video monitor system comprises a transmitting medium, video cameras, monitors, VTR, monitor terminals, a control portion and a transmitting medium having channels of video signals and a data channel coupling these units. The video monitor receives a request of a desired camera and a desired monitor and supplies the data indicative the request. The control portion receives the data indicative of the request and determines one of channels and operates the desired camera and desired monitor thorough the determined one of channels to display a video signal on the desired monitor. The VTR records one of video signals from a desired video camera through determined one of channels. A priority is judged to control one video camera which are requested to be operated by two monitor control terminals at the same time. A diagnostic function for detecting a defect and a location in the transmitting medium and a sequential operation function are also provided. The control portion operates in two modes which can be alternately executed by storing conditional data of two modes. An integrated video monitor system having two video monitor systems mentioned above and a center monitor for displaying a video signal from either of one of video camera of either of the monitor systems is also disclosed.

Video monitor system

A detecting apparatus consists of a covariance calculating section for calculating covariances Sij=.intg..intg..intg.(fi*fj)dxdydt (i,j.epsilon.{x,y,t}) with gradients fx, fy and ft of variable densities of pixels, a characteristic value calculating section for calculating characteristic values by utilizing the covariances to express characteristic changes in the variable densities of the pixels, a first-stage pixel classifying section for classifying the pixels into a FIX type denoting that an observed pixel is positioned in a static region of the dynamic image, a MOT type denoting that the observed pixel is positioned inside the moving region and an ACR type denoting that the observed pixel is positioned in a boundary region between the moving and the static regions, a second-stage pixel classifying section for re-classifying the pixels to match a classification type of the observed pixel with those of pixels surrounding the observed pixel, a contour candidate limiting section for limiting a region occupied by pixels re-classified into the ACR type as a candidate region, and a contour drawing section for drawing a contour of the moving section passing through a middle portion of the candidate region.

Detecting apparatus for detecting a contour of a moving region in a

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Yokohama, Japan

Masaki Sohma