This paper describes a manual method for rapid human decoding of digital data recorded on film. This method provides visual enhancement of tiny digital data for more effective human decision making from image presentations. The Department of Defense has directed the Army, Navy, Air Force and Marine Corps to use the common reconnaissance/ mapping data marking system established by MIL-STD-782B(Wep). All existing data marking systems are to be converted to the binary-coded-decimal system described in this standard. This simple manual method provides a means for the photo interpreter to perform relatively rapid, yet accurate decoding and recording of the binary coded decimal (BCD) data. The tiny BCD bits are magnified by a rear projection system, so that they are easily read by eye and provide sufficient spacing for rapid annotation of each character on a specially designed mask. This mask serves a dual purpose: 1. Grouping the data bits functionally for rapid identification and reading under all specified positions of the CMB. 2. Providing a media for recording the data being read which can be reused or kept for record purposes. The compact projection system is designed for maximum light transmission so that it can use existing diffused light sources. It is simply placed over the tactical reconnaissance film being viewed on any direct viewing light table.
Jerome K. Libby,
"A Method For Rapid Human Decoding Of Digital Data Recorded On Film", Proc. SPIE 0005, The Human in the Photo-Optical System, (1 June 1966); doi: 10.1117/12.946689; https://doi.org/10.1117/12.946689