Real-time density encoder with three primary colors.

A method for pseudocolor encoding of a black-and-white transparency is performed through the simultaneous addition of a direct contrast image, a pseudoreversed image, and a reversed contrast image, each in a different primary color: blue, green, and red, respectively. The physical bases of the method are both specular and diffuse densities, and the method works in real time. The addition of these three color images increases the appreciation range of gray levels in a zone pattern, thereby providing a significant improvement in the information display.