A film digitizer employing a linear CCD imager can provide substantial performance
improvements over a flatbed or drum scanner by measuring many film pixels simultaneously. If
it is required, however, to retain the full quality of the image on the film, careful design of the illumination
system, optics, and electronics is important. This paper will describe the application
of a diffuse illumination system and a three-color CCD imager in a high-resolution film digitizer.
The imager provides up to 8000 pixels per scan line and dynamic range (peak signal-to-darknoise)
of 5000. This technology permits use of a novel means for holding the film, simplifying
the task of mounting the film on the scanner. A brief description will be given of the analog
electronics, digital electronics, and software procedures used to convert raw CCD output to
accurate film density.
James R. Milch,
"Line illumination system and detector for film digitization", Proc. SPIE 1242, Charge-Coupled Devices and Solid State Optical Sensors, (1 July 1990); doi: 10.1117/12.19455; https://doi.org/10.1117/12.19455