The military as well as some commercial users of technical manuals are moving toward a universal requirement of microfilmability for these documents. The halftone photographic process presently utilized for illustration purposes is not suitable for microfilming. The employed solution to this problem is the production of a line-art illustration by manually tracing the various objects of interest in the photographs. This technique results in substantially increased costs for technical manual development meeting the microfilmability requirements. An approach to simplifying the conversion of continuous-tone or halftone photographs to line art has been developed utilizing optical processing techniques. This paper describes the approach, including development of an optimal enhancement filter, the implementation and results of a cost/benefit study.