Patent US 3,988,602

A technique and apparatus for enhancing the data upon a film transparency is presented. The density characteristics of the object film are digitized and shifted to exponentially increase the magnitude and significance of the digitized data. This amplified data is then utilized for producing a second film transparency having increased contrast in accordance with the amplification of the original data. There is also provided means for offsetting the digitized data with respect to a fixed reference such that features of interest may be separated from their background before the final recording of the enhanced film.