SYSTEM AND METHOD FOR DIGITAL
COLOR DYE FILM PROCESSING
This application claims priority under 35 U.S.C. §119(e) of the following United States Provisional Patent Applications: System and Method for Digital Film Development Using Visible Light, Ser. No. 60/174,055, and filed on Dec. 30, 1999; Improved System and Method for Digital Film Development Using Visible Light, Ser. No. 60/173,775, and filed on Dec. 30, 1999; and Method and System for Capturing Film Images, Ser. No. 60/180,477, and filed on Feb. 3, 2000.
This application is related to the following copending ^ United States Patent Applications: System and Method for Digital Film Development Using Visible Light, Ser. No. 09/752,013, and having a priority filing date of Dec. 30, 1999; Improved System and Method for Digital Film Development Using Visible Light, Ser. No. 09/751/378, and 2o having a priority filing date of Dec. 30, 1999; Method and System for Capturing Film Images, Ser. No. 09/774,544, and having a priority filing date of Feb. 3, 2000; and Scanning Apparatus and Digital Film Processing Method, Ser. No. 09/751,403, and having a priority filing date of Dec. 30, 25 1999; and Film Having a Selective Antihalation Layer, Ser. No. 09/522,655, and having a priority filing date of Feb. 3, 2000.
TECHNICAL FIELD OF THE INVENTION 30
This invention relates generally to the field of electronic film processing and more particularly to a system and method for digital color dye film processing.
BACKGROUND OF THE INVENTION 35
Images are used to communicate information and ideas. Images, including print pictures, film negative, documents and the like are often digitized to produce a digital image that can then be instantly communicated, viewed, enhanced, 4Q modified, printed or stored. The increasing use and flexibility of digital images, as well as the ability to instantly communicate digital images, has led to a rising demand for improved systems and methods for film processing and the digitization of film based images into digital images. Film 45 based images are traditionally digitized by electronically scanning a film negative or film positive that has been conventionally developed using a wet chemical developing process, as generally described below.
Undeveloped film generally includes a transparent base 50 and one or more emulsion layers containing a dye coupler and a photosensitive material, such as silver halide, that is sensitive to electromagnetic radiation, i.e., light. In color films, independent emulsion layers are sensitized to different bands, or colors, of light. In general, one or more emulsion 55 layers are sensitized to light associated with the colors of red, green and blue. When a picture is taken, the photosensitive material is exposed to light from a scene material to produce a chemical change in the photosensitive material. The greater the intensity of light interacting with the pho- go tosensitive material, the greater the chemical change in the photosensitive material. The photographic film can then be chemically processed to produce a fixed image of the scene based on this chemical change.
In a traditional wet chemical developing process, the film 65 is immersed and agitated in a series of tanks containing different processing solutions. The first tank typically con
tains a developing solution. The developing solution chemically reacts with the exposed silver halide to produce elemental silver grains in each emulsion layer of the film. The metallic silver forms a silver image within each emulsion layer of the film. The by-product of the chemical reaction combines with the dye coupler in each emulsion layer to create a dye cloud around each developing silver halide grain. The color of the dye cloud is complementary to the band of light to which the emulsion layer has been sensitized. For example, the red sensitized layer typically produces a cyan dye image, the green sensitized layer a magenta dye image, and the blue sensitized layer a yellow dye image. The density of the silver image and the corresponding dye image in each emulsion layer are typically directly proportional to the logarithm of the intensity of light to which the film was exposed. The developing process is generally stopped by removing the film from the developer tank and rinsing the developing solution from the film with water or an acidic solution.
Conventional wet chemical developing processes remove both the silver image and the undeveloped silver halide grains from the film to produce a film negative having only a dye image within the film negative. To remove the silver image and undeveloped silver halide, the developed film is immersed and agitated in a tank of bleaching solution. The bleaching solution chemically oxidizes the metallic silver forming the silver image and converts the silver image into silver halide. The bleached film is then immersed and agitated in a tank of fixer solution. The fixer solution removes the silver halide from the film by substantially dissolving the silver halide crystals. The fixer solution is thereby contaminated with dissolved silver compounds and becomes a hazardous waste byproduct of the wet chemical developing process. The film is then washed, stabilized and dried to produce a conventional film negative. The film negative can then be used to produce a corresponding image on photographic paper by methods known to those skilled in the art.
Conventional film digitization processes scan the film negative using a conventional electronic scanner to produce a digital image that electronically represents the original scene. Conventional electronic film scanners generally operate by directing white light through the film negative. The light interacts with the dye clouds forming the image, i.e. the dye image, and the intensity of the red, green and blue light passing through the film are recorded by a sensor. The sensor data is used to produce the digital image.
A relatively new process under development is digital film processing (DFP). DFP systems directly scan the film during the development process. In particular, instead of scanning the dye image in the film, conventional DFP systems scan the silver image formed in the emulsion layers while the film is developing. In conventional DFP systems, the film is scanned using infrared light. Scanning with infrared light prevents the film from being fogged and allows the developing film to be scanned at different times during the development process in order to acquire image data at different exposure levels.
The DFP scanning process is generally accomplished by measuring infrared light reflected from the developed silver image in the front and back emulsion layers, and measuring the infrared light transmitted through the film. The reflected and transmitted light measurements of the film provide image data from the blue, red, and green sensitized emulsion layers, respectively. The measured reflected and transmitted light data is processed to produce the digital image.
SUMMARY OF THE INVENTION
One embodiment of the invention is a digital color dye film processing system for developing and scanning silver