1 Watson, A. B., Solomon, J. A., & Ahumada, A. J., Jr. (1994). The visibility of DCT basis functions: effects of display resolution. Proceedings, Data Compression Conference, Snowbird, Utah: IEEE Computer Society Press, 371-379. Visibility of DCT basis functions: Effects of display resolution. Andrew B. Watson Joshua A. Solomon Albert J. Ahumada, Jr. NASA Ames Research Center Moffett Field, CA 94035-1000 beau@vision.arc.nasa.gov Introduction The JPEG, MPEG, and CCITT H.261 image compression standards, and several proposed HDTV schemes, employ the Discrete Cosine Transform (DCT) as a basic mechanism [1, 2]. Typically the DCT is applied to 8 by 8 pixel blocks, followed by uniform quantization of the DCT coefficient matrix. The quantization bin-widths for the various coefficients are specified by a quantization matrix (QM). The QM is not defined by the standards, but is supplied by the user and stored or transmitted with the compressed images. The principle that should guide the design of a QM is that it provide optimum visual quality for a given bit rate. QM design thus depends upon the visibility of quantization errors at the various DCT frequencies. In recent papers, Peterson et al. [3, 4] have provided measurements of threshold amplitudes for DCT basis functions at one viewing distance and several mean luminances. Ahumada and Peterson [5] have devised a model that generalizes these measurements to other luminances and viewing distances, and Peterson et al. [6] have extended this model to deal with color images. From this model, a matrix can be computed which will insure that all quantization errors are below