The effects of picture size and definition on perceived image quality

The so-called square root integral (SQRI), which describes the effect of resolution on perceived image quality, is further evaluated to describe the effect of picture size on subjective image quality. This is possible by taking the effect of display size into account in the modulation threshold function of the eye, appearing in the integrand of the SQRI. In this way an excellent correlation is found between subjective image quality and calculated SQRI value for recent measurements by J.H.D.M. Westerink and J.A.J. Roufs (SID Dig., vol.19, p.360-3, May 1988). Data indicate that there is an optimum display size or an optimum viewing distance for a given number of displayed pixels. The optimum conditions can be calculated with the aid of the SQRI.<
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