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[Author] Yuta KAWAMURA(2hit)

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  • The Influence on Humans of Long Hours of Viewing 3D Movies

    Yuta KAWAMURA  Yusuke HORIE  Keisuke SANO  Hiroya KODAMA  Naoki TSUNODA  Yuki SHIBUTA  Yuki KAWACHI  Mitsuho YAMADA  

     
    LETTER-Vision

      Vol:
    E95-A No:8
      Page(s):
    1306-1309

    Three-dimensional (3D) movies have become very popular in movie theaters and for home viewing, To date, there has been no report of the effects of the continual vergence eye movement that occurs when viewing 3D movies from the beginning to the end. First, we analyzed the influence of viewing a 3D movie for several hours on vergence eye movement. At the same time, we investigated the influence of long viewing on the human body, using the Simulator Sickness Questionnaire (SSQ) and critical fusion frequency (CFF). It was suggested that the vergence stable time after saccade when viewing a long movie was influenced by the viewing time and that the vergence stable time after saccade depended on the content of the movie. Also the differences were seen in the SSQ and CFF between the movie's beginning and its ending when viewing a 3D movie.

  • Accuracy of Smooth Pursuit Eye Movement and Perception Rate of a False Contour While Pursuing a Rapidly Moving Image

    Yusuke HORIE  Yuta KAWAMURA  Akiyuki SEITA  Mitsuho YAMADA  

     
    LETTER-Vision

      Vol:
    E94-A No:2
      Page(s):
    542-547

    The purpose of this study was to clarify whether viewers can perceive a digitally deteriorated image while pursuing a speedily moving digitally compressed image. We studied the perception characteristics of false contours among the various digital deteriorations for the four types of displays i.e. CRT, PDP, EL, LCD by changing the gradation levels and the speed of moving image as parameters. It is known that 8 bits is not high enough resolution for still images, and it is assumed that 8 bits is also not enough for an image moving at less than 5 deg/sec since the tracking accuracy of smooth pursuit eye movement (SPEM) is very high for a target moving at less than 5 deg/sec. Given these facts, we focused on images moving at more than 5 deg/sec. In our results, the images deteriorated by a false contour at a gradation level less than 32 were perceived by every subject at almost all velocities, from 5 degrees/sec to 30 degrees/sec, for all four types of displays we used. However, the perception rate drastically decreased when the gradation levels reached 64, with almost no subjects detecting deterioration for gradation levels more than 64 at any velocity. Compared to other displays, LCDs yielded relatively high recognition rates for gradation levels of 64, especially at lower velocities.