This paper proposes a method for estimating the scene illuminant spectral power distributions of multiple light sources under a complex illumination environment including natural and artificial illuminants. We assume that curved object surfaces of dielect materials are illuminated by the multiple light sources from different directions. Light reflection from the surfaces is described by the dichromatic reflection model, in which the specular reflection component includes much information about scene illuminant. First, we describe a high-dimensional spectral imaging system. Second, we propose several methods for detecting the candidates of specular highlight areas in the captured image, and determine the most proper highlight areas on the object surfaces. Third, we present an estimation algorithm of illuminant spectra from the detected highlight areas. All the estimated illuminant spectra are summarized into some classes based on a similarity measure. The feasibility of the proposed method is shown in experiments using real objects under several light sources.
The under coated layer (UCL) in xerographic photoreceptor has various functions so as to prevent charge injection from Al substrate to charge generation layer (CGL) and to remove charge accumulation on the CGL. Metal oxide particles are commonly used as UCL, but its properties are not good enough. It is known that certain dyes are added to improve the properties of UCL. In this paper, the complex impedance spectroscopy analysis and Time-of-Flight (TOF) technique were carried out to investigate electrical charge transport behavior of metal oxide based UCL film. An effect of dye added in the film was also discussed.
Nowadays LED lights have been spread rapidly in use for efficiency and life time. However, sometimes LED lights obviously degrade color appearances between different spectral conditions because of the several times bigger spectral color difference than traditional light sources i.e. fluorescent lights. CRI (Color Rendering Index) defined by CIE (Commission Internationale de l'Eclairage) is one of the available means, whereas it is not suitable for nowadays practical color data interchanges between different lighting conditions together with different color reproductions. Quantitative evaluations of light sources and color reproductions are needed urgently to solve the problems. In this study, we introduce a Hyper Spectral Sensor featured with excellent performances for spectral measurements and propose an index to show the quality of color appearances based on the values of CIE L*a*b* uniform color space transferred from the obtained data. The experimental results are confirmed by additional subjective evaluations. It was confirmed that the proposed quantitative evaluations are effective and we also found that it is effective to reduce the problem by minimizing the transitions of spectral distribution of light sources and color reproductions.
In this paper we show the history, technology and one of the projects that have been carried out till December 2012, using imaging technology based on large-flatbed scanning with carefully designed components to handle a wide variety of objects. The main features of these large flatbed scanners are : (i) high color fidelity with a color difference of about 1.0-1.5 for IT8 charts, (ii) minimal light irradiation on the object (less than 5% per scan of the allowable exposure based on museum standards), (iii) high spatial resolution capable of detecting microscopic scale areas (5-80microns), (iv) fast and cost effective to digitize hundreds and thousands of objects in museums and national libraries, (v) applicable to wide range of objects of various shapes, sizes and surface characteristics (e.g. 2D to 3D objects;small to large;and dark to shiny), (vi) non-contact and non-invasive, (vii) can produce analytical information (e.i. spectral and colorimetric). Finally we give a brief introduction to scientific recording of the Kannondo temple of Ninnaji, a UNESCO world heritage in Kyoto.
Toppan Forms Co., Ltd, an information management company, has tackled the development of application for digital printing. Finally, we started a new business to reproduce Japanese traditional picture scroll by digital printing press. Picture scrolls comparable to national treasures or important cultural assets are kept under lock and key in museums, shrines or temples. We rarely appreciate them without special displays, nor enjoy opening and rolling them up by ourselves though it is an original way of a fan. Nowadays there are conventional copies which versions are black and white, micro copied, brochure, or high-class luxury. We precisely re-created original ones by means of merging the newest digital technologies and Japanese traditional manufacturing techniques and are able to offer our high quality copies at a more reasonable price. Akiyama Mitsukazu, a professor emeritus at University of Tokyo and foremost authority on researching picture scroll, cooperated with us as a supervisor. He directed re-creating color and bind. He also introduced us to commentary authors and the owners of original scrolls. We use Bagasse in our copies to re-create Japanese paper texture. It might be easy to print only continually on roll paper even if it were 10 meters or 20 meters in length without replenishing, but we need to correct and equalize the color tone of each film we borrow from owners before we convert them into digital data. We also developed software with SANYO Electric Co., Ltd, which corrects color, distortion between right and left and bridge of each films.
In March 2007, Canon Inc., and NPO Kyoto Culture Association launched “Cultural Heritage Inheritance Project,” hereafter Tsuzuri Project. The aim of the project is to create high-definition facsimiles of Japanese cultural properties, such as folding screens and sliding doors, created mainly from the Azuchi-Momoyama period to Edo period, by using Canon's latest digital technology and traditional skills of artisans in Kyoto. Those facsimiles are donated to the places where have particular connections with the originals, such as temples and shrines. Also we use those facsimiles as to familiarize the people with Japanese cultural properties. Facsimiles are now variously-used by donees and through introducing the use of the facsimiles we seek the meaning and importance of this project.
Digital archiving for the purpose of protection and inheritance of historical cultural properties gains momentum in recent years. Japanese swords are highly valuable cultural properties related to historical characters and background, thus digital archiving and browsing have been strongly desired. Devices to achieve Japanese swords' excellence, i. e., “unbreakable, unbendable, and ultra-sharp” also form beauty of the sword. However, it is difficult for non-experts to appreciate the beauty, because reading aura of colors and patterns while changing relative posture of illumination, sword and eyes is important in the aesthetics of Japanese sword. We develop a Japanese sword digital archiving system with multi-angle and multi-band spectrometric capturing functions, as well as color and brightness correction and image synthesis. The system can display the appearance of the Japanese sword in expert perspective. This paper describes functions and architecture of the system and effectiveness of archiving images.
Digital technology has become popular in the motion picture industry. On the other hand, technology to preserve huge amount of digital data of motion pictures for a long term has not been developed. There is an urgent demand to safely preserve motion pictures made digitally for a long time. Photographic film technology that has been developed with motion picture can integrate with digital technology and assume a new mission to preserve digital data, making up for the weakness of digital technology in long term preservation.