A black-and-white photograph contains, in its varying intensities of gray, much more information than can be extracted by the human eye, which can distinguish only 15 to 20 gray shades. Transforming the gray scale into a chromatic scale in which each intensity level is presented as a different color makes it possible to transmit more of the image information--a possibility being investigated for use in medicine, criminology, and aerial reconnaissance. This paper describes a method that requires only two separation steps (red and blue) and can be handled by a modestly equipped photo laboratory. This pseudocolor process produces a continuous line through color space from adjacent densities in the original. If desired, it can be transformed in various ways by changes in photographic materials, filters, and exposures. (Presented at the 15th Annual Symposium of the Society of Photo-Optical Instrumentation Engineers, Anaheim, September 1970.) 6 pp. Ref.