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Displaying 1-10 of 10 articles from this issue
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Article type: Cover
Pages Cover1-
Published: November 22, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (14K) -
Article type: Index
Pages Toc1-
Published: November 22, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (41K) -
Mamoru Takamatsu, Santarou Nakajima, Yoshio Nakashima, Yuukou HoritaArticle type: Article
Session ID: HIR2001-91
Published: November 22, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSOur visual characteristics are affected by various visual environments. In this experiment, we examine how object colors look in dense fog. Namely, 5 subjects with normal color vision evaluated their color perception of object color both in the presence of fog and in the absence of fog at various illuminance levels. Subject's task is to match the apparent color of 10 standard-color-cards in dense fog with the Munsell color. In the presence of fog, apparent color showed a drastically decrease both in the chroma and in the value. Namely, their color perception shift from chromatic color to achromatic color. This tendency becomes more conspicuous as the surface illuminance level diminishes.View full abstractDownload PDF (407K) -
Santaro Nakajima, Mamoru Takamatsu, Yoshio Nakashima, Kazuhiro SassaArticle type: Article
Session ID: HIR2001-92
Published: November 22, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSTraffic information boards have a vital role in promoting safe and efficient road traffic, by providing the drivers with relevant traffic information on a real-time basis. To achieve good visibility, we must know the optimum number of display colors and chromaticity regions so that the drivers can correctly recognize displayed information in a short time. We attempted to determine an optimum number of display colors based on the categorical color technique, as well as to define the chromaticity regions for display colors so that a given color is most effectively discriminated from the others. The results showed that the optimum number of display colors is nine.View full abstractDownload PDF (495K) -
Yoriko Kawakami, Koichi Mori, Akira Tsukada, Yoshichika Baba, Kazuo Sa ...Article type: Article
Session ID: HIR2001-93
Published: November 22, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSAn Ehrenstein figure that consists of radial line segments is a visual illusion that a circle which is brighter than the background is perceived, even though the two regions are identical in brightness. This circle is a subjective circle which physically does not exist. In order to understand that the subjective circle is brighter than the background, we measured the perceived brightness of the part which faces line end and part which faces the line of the stripe. We also examined the difference between the brightness for the case in which some regions are surrounded by the line end and case in which it is not so.View full abstractDownload PDF (619K) -
Hisanori Nahata, Akira Tsukada, Yoshichika Baba, Kazuo SasakiArticle type: Article
Session ID: HIR2001-94
Published: November 22, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSOverall (average) adaptation and local adaptation exist in human visual system. In addition, a physiological experiment suggests that the midrange adaptation, which is different from above two adaptations, may occur in human visual system. The present study was carried out to examine the existence and the characteristics of the midrange adaptation by comparing subjective brightness of two spots. The results indicate that the midrange adaptation occurs when a step change in luminance exists on the fovea, but not when it exists out of the fovea.View full abstractDownload PDF (684K) -
Akira Kushida, Mariko Inaba, Yuukou Horita, Kazuhiro Honda, Tadakuni M ...Article type: Article
Session ID: HIR2001-95
Published: November 22, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSWe analyze the region of interest of the coded stereoscopic image by using the information of the eye path tracking. The information of the eye path tracking is obtained from the eye camera system. From the result of the assessment test, the stationary viewing point of human observer is sometimes strongly focused on the object region which has disparity information. This tendency is affected to the picture contents, especially the face region. Moreover, the perceptual difference of the disparate quality in left- and right-image is not obtained from the information which is derived from the distribution of the stationary viewing points. In addition, the distribution of the stationary viewing points is not changed significantly between the stereoscopic viewing condition and its 2-dimensional viewing condition.View full abstractDownload PDF (1926K) -
Jun'ichi Ohnishi, Takamichi Miyata, Yuukou Horita, Kazuhiro Honda ...Article type: Article
Session ID: HIR2001-96
Published: November 22, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSWe consider the visual perception of the video qualities which are obtained from the constant bit-rate coding and the constant frame quality coding. In our experiment, we employ the MPEG-2 coding method as the constant bit-rate coding and the quality-oriented JPEG coding method for the constant frame quality coding. The Mean Opinion Score is obtained from the subjective assessment test and the frame qualities of the coded video are estimated from the quality evaluation model of still pciture. As the result, the video quality obtained from the constant frame quality coding isn't same as the requested quality. Moreover, the relation between the constant bit-rate coding and the constant frame quality coding is strongly affected of the video contents.View full abstractDownload PDF (644K) -
Tetsuro KUGEArticle type: Article
Session ID: HIR2001-97
Published: November 22, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSA new image coding method utilizing the wavelet transform, JPEG2000, has been developed. In this report, we consider several types of visual distortion observed in moving HDTV pictures and ultra-high definition pictures compressed by wavelet transform coding, and describe measures to reduce them. So-called "flicker artifacts" are visually decreased by visual weighting and the mechanism is interpreted by Weber's law. The characteristic distortion caused by the combination of subband decomposition and the interlaced TV signal structure is discussed, and a preprocessing method is proposed to counter it. The relation between the resolution levels of the subband decomposition and the distortion is investigated by coding experiments on ultra-high definition pictures.View full abstractDownload PDF (1085K) -
Article type: Appendix
Pages App1-
Published: November 22, 2001
Released on J-STAGE: June 23, 2017
CONFERENCE PROCEEDINGS FREE ACCESSDownload PDF (86K)
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