Pseudocolor as a Means of Image Enhancement

For human observers the number of distinguishably different colors is much larger than the number of distinguishably different shades of gray. Therefore, if the scale of grays in a complex black‐and‐white image, such as an X‐ray, is transformed into some suitable scale of colors, perception of the details in that image will be greatly enhanced. In one versatile but expensive method of producing such pseudocolor images, the black‐and‐white image is photo‐clcctrically scanned and a computer is used to produce three pseudocolor separation positives (or negatives) directly on 35 mm film. A simpler and inexpensive method has been developed which uses purely photographic procedures. Examples of results with this procedure applied to chromosome photomicrographs. X‐ray films, and pathological specimens are presented.