Katsumi Asakawa

False color signal reduction method for single chip color video cameras

Video devices such as VCRs have been increasingly digitalized and it is necessary to improve the picture quality of cameras to cope with digitalized video devices. For the single-chip color video cameras with a line sequential color difference signals system, which are primarily used at present as the camera units for home-use and ITV (industrial television), the authors have studied a luminance signal generation method for low attenuation of high-frequency components using the correlation of the ratio between the chrominance signal and the luminance signal in localized image areas. Using a luminance signal with low attenuation of the high-frequency components, the writers have studied a method of reducing the false color signal generated in single-chip color video cameras through the application of image simulation, and have obtained a favorable result as reported in the present paper. >

High-precision color transformation system

Low priced consumer video devices have become increasingly common. Furthermore, with the promotion of digital and multimedia devices, the pictures obtained from such devices are not only subjected to printing, display and editing, but also are transmitted through network systems. However, the transmission of color information involves the problem of color developments which are different in type, calling for the study of the transmission of color information in the standard color space, independent of the device. By means of the conventional system, which jointly uses a low-capacity 3-dimensional LUT (look up table) and linear interpolation, it is not possible to improve the transformation precision unless the capacity of the 3-dimensional LUT is increased. Therefore the present study investigates upgrading the transformation precision such as by expanding the transformation region, correcting the color displacement, using a 3-dimensional LUT with the output values arranged at equal intervals of space, and improving the dark section. This has led to the circuit size slightly increasing due to the added 3-dimensional LUT and the need for dividers; excellent color transformation is assured. The color difference between the original image and the reproduced image after repeating the transformation ten times can be reduced to 30% of the conventional system, providing excellent results in terms of the subjective estimation of gradation continuity, color displacement, etc. >

Development Of Card-sized Digital still cameras

Digital still cameras (DSCs) have attracted a great deal of public attention as input tools for images. However, conventional DSCs are only extensions of compact cameras using 35 mm film, and are not compact enough for easy portability to take photos, anytime, anywhere. For the purpose of offering a more portable DSCs, the authors have developed a card-sized digital still camera (CDSC). It is portable (62/spl times/107/spl times/8.5 (12.3) mm) and has a flash memory which stores 15 pictures. The authors have also developed original software for the CDSC which has a new signal processing system which can offer high quality pictures.

Super-wide-angle cameras by image synthesis

Synthesizing left and right images is a popular method getting a wide-angle image, and this synthesis has conventionally been done by putting two images side by side. The conventional technique thus restricted the arrangement of the cameras and objects. The paper proposes a new method of acquiring a super-wide-angle image by synthesizing images. Left and right rectangular images are transformed into trapezoidal images, and the transform formula is derived from the relation between the position of the cameras and the object. This method enables the cameras to be set up anywhere and it provides an image nearly twice as wide as the one obtained with a conventional camera, giving an image with which is easy to see perspective. The measures reported in the paper made it possible to achieve a wide-angle-imaging system suitable for consumer products. By preventing discontinuity between images at their joint, it can create wide-angle images as good as those taken from a single viewpoint regardless of the positions of the cameras and the objects. Using a prototype video camera employing the image simulation of the new system, it has been established that the new system provides wide images with an angle of more than 180 degrees and good clarity. >

Development of very bright LC projector

A very bright, compact LC projector with a multi-scanning function has been developed by using LC panels with a scattering capacity called LCPC (liquid crystal polymer composite) and by reducing the circuit scale drastically using two newly developed LSIs.