Digital Intermediate

Digital intermediate (typically abbreviated to DI) is a motion picture finishing process which classically involves digitizing a motion picture and manipulating the color and other image characteristics. It often replaces or augments the photochemical timing process and is usually the final creative adjustment to a movie before distribution in theaters. It is distinguished from the telecine process in which film is scanned and color is manipulated early in the process to facilitate editing. However the lines between telecine and DI are continually blurred and are often executed on the same hardware by colorists of the same background. These two steps are typically part of the overall color management process in a motion picture at different points in time. A digital intermediate is also customarily done at higher resolution and with greater color fidelity than telecine transfers.

Although originally used to describe a process that started with film scanning and ended with film recording, digital intermediate is also used to describe color grading and final mastering even when a digital camera is used as the image source and/or when the final movie is not output to film. This is due to recent advances in digital cinematography and digital projection technologies that strive to match film origination and film projection.

In traditional photochemical film finishing, an intermediate is produced by exposing film to the original camera negative. The intermediate is then used to mass-produce the films that get distributed to theaters. Color grading is done by varying the amount of red, green, and blue light used to expose the intermediate. This seeks to be able to replace or augment the photochemical approach to creating this intermediate.

The digital intermediate process uses digital tools to color grade, which allows for much finer control of individual colors and areas of the image, and allows for the adjustment of image structure (grain, sharpness, etc.). The intermediate for film reproduction can then be produced by means of a film recorder. The physical intermediate film that is a result of the recording process is sometimes also called a digital intermediate, and is usually recorded to internegative (IN) stock, which is inherently finer-grain than camera negative (OCN).

One of the key technical achievements that makes the DI possible is the look-up table (aka "LUT"), which can be made to mimic how the digital image will look, once it's printed onto normal release print stock. DI facilities generally allow comparing the digital image directly to a print on the same screen, ensuring precise calibration of the process.

The digital master, created during the Digital Intermediate process, can be recorded to very stable yellow-cyan-magenta (YCM) separations on black-and-white film with an expected 100-year or longer life.

The digital master is often used as a source for a Digital Cinema Initiatives (DCI) compliant distribution of the motion picture for digital projection.