No.2（2007）5.Development of a high performance closed circuit TV

Hiroshi Yokota, Katsuhiko Hibino

We succeeded in developing a small, light, high performance closed circuit TV at low cost. The closed circuit TV is welfare equipment for amblyopic people who account for most of the visually handicapped and especially for the severely amblyopic. It is often set up in libraries and the official body of Facilities for Senior Citizens and the Disabled etc. Old goods have expanded characters and images by optical zoom. As the structures are formed from several expensive optical lenses, there are many of these expensive, large fixed types. Then, assuming mobile usage, a small, light product to be carried with a notebook PC was planned. It connects with the USB port of the notebook PC, and is managed by software on the PC, and as power is supplied by the USB port it is unnecessary for the camera to have a power supply. Moreover, we used a board lens for CMOS cameras of 1.3 million pixels to keep the price low. Expansion uses image data processing technology, and by software managed on the notebook PC, digital zoom is utilized. The problem when expanding by digital zoom is deterioration of the image chiefly from mixing of the noise element from when taking the image. Then, we developed software that removed the random noise by spatial filter processing and temporal axis filter processing for expanding by third interpolation processing. We achieved good results in making a trial product of the closed circuit TV that maintained image quality of the original picture image and enabled high magnification of characters.

Keywords

closed circuit TV, digital zoom, image data processing

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