EVALUATION OF SUBJECTIVE IMAGE QUALITY WITH THE SQUARE-ROOT INTEGRAL METHOD

After a short survey of some other metrics of perceived image quality, the square-root integral (SQRI) is described. In this metric a fixed mathematical expression for the contrast sensitivity of the eye is used. With the SQRI method the effect of various display parameters, such as resolution, addressability, contrast, luminance, display size, and viewing distance, on subjective image quality can be taken into account. Experimental data of subjective image quality, measured by various authors, are compared with calculated SQRI values. From the comparison it appears that the calculated SQRI values show a good linear correlation with perceived subjective image quality not only at variation of resolution but also at simultaneous variation of other display parameters. © 1990 Optical Society of America.