System and method for processing images to emulate film tonescale and color

A method for converting a sequence of scan-only film captured images into a sequence of modified images providing the appearance of images captured by a photographic film reproduction system;

• the photographic film reproduction system being of the type that includes photographic motion picture negative film printed onto a motion picture print film that is displayed, or a reversal motion picture system in which the reversal film is displayed, or a photographic motion picture film electro-optically scanned to standard format video by a telecine and further displayed, or a photographic motion picture film electro-optically scanned by a scanner suitable for producing digital data intended for additional digital image manipulation and further preparation as a digital master for electronic distribution such as digital theatrical projection or various types of broadcast video;
• or recorded out to another photographic film to be used as a printing master for producing distribution optical prints for theatrical projection, said method comprising the steps of:
• a) photographically capturing a sequence of images on a scan-only film;
• b) chemically processing the scan-only film to produce photographic film images;
• c) electro-optically scanning the processed photographic film images to produce electronic images in either video or data formats;
• d) transforming scan-only film captured image video or data into signals representative of the scan-only film's optical scanning densities;
• e) transforming the scan-only film's optical densities with a linear function that represents the film's interimage interlayer effects to produce uncorrelated color optical density data;
• f) transforming the scan-only film's uncorrelated color optical densities with a non-linear function that emulates the film's uncorrelated characteristic density response to scene exposure to produce linearized exposure data and neutral-corrected scan-only film captured images;
• g) transforming the neutral-corrected scan-only film captured images with a non-linear function that renders the exposure-corrected scan-only film captured images with a tone scale of the film reproduction system to produce tonescale-corrected scan-only film captured images;
• and
• h) transforming the tonescale-corrected scan-only film captured images with a linear function that emulates a film color look provided by the film reproduction system to produce modified images that provide the appearance of an image that had been captured with the film reproduction system, and wherein the above transforming steps are referenced to scanned film densities of a photographic film used in the photographic film reproduction system.

A system for converting a sequence of scan-only film captured images into a sequence of modified images providing the appearance of images captured by a photographic film reproduction system;

• the photographic film reproduction system being of the type that includes photographic motion picture negative film printed onto a motion picture print film that is displayed, or a reversal motion picture system in which the reversal film is displayed, or a photographic motion picture film electro-optically scanned to standard format video by a telecine and further displayed, or a photographic motion picture film electro-optically scanned by a scanner suitable for producing digital data intended for additional digital image manipulation and further preparation as a digital master for electronic distribution such as digital theatrical projection or various types of broadcast video;
• or recorded out to another photographic film to be used as a printing master for producing distribution optical prints for theatrical projection, said system comprising:
• a) a scan-only film for capturing a sequence of images;
• b) a chemical processor for processing the film;
• c) an electro-optical scanner for scanning the processed film images and obtaining electronic images in either video or data formats;
• d) a processor for converting the scan-only film captured image video or data into signals representative of the film's optical scanning densities;
• e) a first linear processor for transforming the scan-only film optical densities with a linear function that represents the film's interimage interlayer effects to produce uncorrelated color optical density data;
• f) a first non-linear processor for transforming the scan-only film uncorrelated color optical densities with a non-linear function that emulates the film's uncorrelated characteristic density response to scene exposure to produce linearized exposure data that yields neutral-corrected scan-only film captured images;
• g) a second linear processor for transforming the neutral-corrected scan-only film captured images with a linear function that emulates a film exposure of the film reproduction system to produce exposure-corrected scan-only film captured images;
• h) a second non-linear processor for transforming the exposure-corrected scan-only film captured images with a non-linear function that renders the exposure-corrected scan-only film captured images with a tone scale of the photographic film reproduction system to produce tonescale-corrected scene film density values;
• and
• i) a third linear processor for transforming the tonescale-corrected scene film density values with a linear function that emulates a film color look provided by the photographic film reproduction system, resulting in modified images that provide the appearance of an image captured with the photographic film reproduction system, wherein the transformation steps are referenced to scanned film densities of a film used in the photographic film reproduction system.