Visual system in the brain is considered with special emphases on the localized spatial frequency analysis which is performed in the primary visual cortex, and the feedback neural connections which is widely found along the visual pathways. Our model for the feedback neural connections and that for the simple cell binocular response are described.

View full abstract

[in Japanese]

View full abstract

Recently, the mechanism of visual information processing has been intensively studied at the molecular level. The application of such biological functions will lead to the development of models for new functional devices. In this study, we prepared an artificial molecular membrane model, which has a similar function to the retina, for the first time. A feature of the model is the conversion of light information to electrical oscillation signals through structural changes of the membrane initiated by a photochemical reaction. This model is expected to be useful in such applications as parallel information processing, etc.

View full abstract

A p x 64 kbit/s standard video codec for videophone and videoconferencing applications has been developed, conforming to CCITT Recommendations related to audiovisual teleservices. This paper describes hardware implementation after a comparison between two promising design methods i.e. DSP-based and LSI-based implementation. As a result of the comparison, LSI-based implementation has turned out to be more advantageous for videoconferencing codecs. By optimum partitioning of codec functions, a new chip set is developed, resulting in a small-sized codec.

View full abstract

This paper describes an electrophotography process control method which includes the latent-image voltage control system using a Neural Network to estimate the OPC surface voltages, as well as a the toner supply control system using Fuzzy theory to decide the toner supply quantity. In the latent image control system, the charging and exposing characteristics of the OPC drum were taught to the Neural Network, which decides the appropriate charging voltage and exposing power to produce the necessary surface voltage. As a result, those voltages can be controlled to within ± 10V of the target voltage. Furthermore, by applying Fuzzy theory for the toner supply control system, fractuation of image density is reduced to 1/6 to 1/9.

View full abstract

Color separation work with a color scanner usually requires experience and knowledge acquired over many years, Therefore, the shortage of skilled operators has caused a problem. In addition, productivity cannot be increased because of taking time for handling a traditional scanner. For these reasons, we have developed a color scanner Fujix LuxScan 4500 which has realized ease of operation and high productivity by flatbed-type scanner using CCD line sensors as image reading devices and user-friendly interface. In this paper, we describe a high accuracy CCD compensation method, a color processing method satisfing a color scanner function and an auto set-up algorithm which sets set-up parameters automatically by analyzing a color original.

View full abstract