To ensure that each scene of a motion picture has the same basic lighting, a grayscale chart is typically recorded on one or more frames of film or video tape at the beginning of the scene by the camera recording the scene. A grayscale chart (or gamma chart) is a commonly known quality control element having a range of calibrated neutral density (i.e., gray) reflectance values from black to white. These known neutral density reflectances are used during the transfer process to enable film-makers to visually assess and maintain proper color balance, brightness and contrast while also compensating for effects that variables in film stock, film age, and lighting have on the color images.
Images from film may be transferred to video tape or to computer-readable media to be used, for example, in an editing system, such as the Avid Symphony nonlinear editing (NLE) system, where they may be digitally edited. An editor uses the NLE system to create a composition including segments from a digitized version of the film. The data that represents the composition commonly is referred to as "meta-data" and may be stored in a data file or in a database. The digital editing system may provide, for example, a cut list that specifies how the negative may be cut to produce the motion picture. Using the cut list, the negative is then cut and rearranged in the correct order. This negative becomes what is commonly known as the "master negative." The master negative is used to create a final color copy of the motion picture. The final color copy may be used by a transfer device to transfer images from the final color copy to a distribution medium.
After or during transfer of images from film, color correcting is typically performed. This color correction is typically performed by an expert called a colorist. Color correction may be performed using several different devices during the production of a motion picture. For instance, color correction may be performed when film is transferred to video tape or to computer readable media using a telecine. Color correction also may be performed when the film is transferred to various other media such as digital versatile disk (DVD), television signals format (e.g., PAL and NTSC), high definition television (HDTV) format, and the like. For each type of transfer, a different color correcting device may be used. Currently, various color correcting devices and processes are used on an ad hoc basis and operate in isolation.
USPTO Backgrounds
USPTO Backgrounds