A model of image quality evaluation process is proposed. And various problems to realize quality evaluation by this model are discussed. Since this model is formally isomorphic with that of factor analysis, an experiment is performed to examine this relationship to be exist in reality. This is verified through the image quality evaluation of a television receiver varying brightness and cotrast. Two experiments illustrating the multidimensional structure of image quality are introduced.

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Resolution is one of the main factors for evaluating displays. MTF (Modulation Transfer Function) is commonly used to describe resolution. The authors have developed an automatic MTF measurement device, which utilizes two different measurement methods; one uses moving sinusoidal bar patterns of various frequencies and the other uses Fourie Transformation of an impulse response. Using the device, MTFs have been measured under various conditions (e.g. different DC levels). MTFs of some HDTV CRT displays are also discussed.

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A new mathematical spatio-temporal model of the human vision system has already been proposed which can quantitatively simulate spatio-temporal visual responses (contrast sensitivity characteristics) to flickering sinusoidal waves. This model developed from the former vision model for still images. In this paper, this model is applied to drifting sinusoidal waves, and it is shown that the X-channel's and the Y-channel's spatio-temporal frequency characteristics of the vision model are in good agreement with two kinds of experimental results. This result suggests that the model can also be used for simulating actual visual responses to more general moving patterns.

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We investigated about the multi-value effect and the image quality estimated method of the ordered dither which we used to display the gray image by little level display device. Now, first we represent the best gray quantization dither image by the relation between dither matrix size and the clement coefficent. Second we represent the relation between input image and the dither image by the variance and the correlation coefficent. Next we represent the relative dither intensity by the ratio of the input image's power and the dither image's power. Therefore we report about the multi-value display and the estimated method of the ordered dither.

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This article reports effects of flickering border regions on filling-in. It demonstrates that such a flicker leads to almost the same average psychophysical performance as if it were not at all present. In contrast, a border region of same shape, but not flickering, significantly delayed the filling-in, both for black and white regions. This effect could be based on the dynamics of neurons which, when changing their activities according to the changing stimulus in the presence of a flicker, for a short period of time seem to respond to equiluminance. This result contributes to the clarification of the mechanisms underlying the filling-in process.

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Stereoscopic images are no longer judged as true to life when the size of the display screen is insufficient. Human beings reproduced in reduced size appear as if they were animated puppets (puppet theater effect). This paper describes a subjective evaluation experiment carried out to clarify under which input-output conditions of stereoscopic images this effect is significant. Results show that the puppet theater effect is relaxed when the geometric perspective and the stereoscopic depth of the displayed scenery are matched to natural viewing depth conditions. On the other hand, disparity settings required to establish correct depth reproduction generally caused annoying side effects (e.g increased eye-strain). It is concluded that this disparity correction should only be applied for short distance shots watched at near viewing distances, e.g., in conditions typical of video phone applications.

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