Graphical user interface for color correction

#Digital non-linear editing (DNLE) is a process by which digital media may be edited. DNLE, as the name implies, is performed on digital media stored as data in digital media files on a digital random access medium. DNLE may be conducted in a non-linear fashion because the digital media files in which the digital media is stored can be randomly accessed. Thus an editor may access a piece of the digital media without having to proceed sequentially through other pieces of the digital media stored in the same or other digital media files. More than one editor also may be able to access different pieces of the same digital media contemporaneously. The digital media may be a digitized version of a film or videotape or digital media produced through live capture onto a disk of a graphics or animation software application. Example commercial DNLE systems include the Media Composer® or the Avid® Symphony™ video production system or NewsCutter® news editing system available from Avid Technology, Inc. For a more detailed description of DNLE, see Digital Nonlinear Editing, New Approaches to Editing Film and Video, 1993, by Thomas Ohanian.

#Color modification is a class of operations that may be performed both to correct color errors due to process errors and to adjust the colors used in the video for artistic expression. Such color modifications may include enhancing contrasts or color in an image to give a program an overall “look,” or applying special effects to selected segments. Other color modifications may be made by an editor during an editing session to correct problems with color or lighting resulting from the source of the media. Such corrections may include color balancing for camera and lighting differences, correcting for film processing differences, matching colors and tones from shot to shot, or adjusting video levels for differences in source tapes, source decks, etc.

#Digital images are comprised of an array of picture elements called pixels. For a given image, color modifications may be applied to all pixels in the image or pixels comprising a portion of the image. In digital video signal processing, a variety of data formats can be used to represent the color of pixels within a digital image. Formats may be classified into two major categories: composite signals and component signals. Component formats represent a color as multiple components, each component defining a value along a dimension of the color space in which the color being represented is defined. A composite video is an analog signal that uses a high frequency subcarrier to encode color information. The subcarrier is a sinewave of which the amplitude is modulated by the saturation of the color represented by the signal, and the hue of the color is encoded as a phase difference from a color burst. Analog composite signals generally are used to broadcast television video signals.

#In the drawings,

#FIG. 1 is a block diagram illustrating relationships between source data structures and source media;

#FIG. 2 is a diagram illustrating relationships between composition data structures in a composition;

#The following detailed description should be read in conjunction with the attached drawing in which similar reference numbers indicate similar structures. All references cited herein are hereby expressly incorporated by reference.

#A DNLE may track or have access to information that indicates how segments of media in a composition may be related by the source of the media data that they represent. This information may be used to apply color modification to multiple segments at the same time. Such modification is referred to herein as source color modification.

#The relationships between segments of a source media in a composition are represented by references to source data structures representing media that can be combined or composed into a multi-media composition. Color modifications, including source color modifications, are generally defined within the context of a composition. Compositions are represented by composition data structures or components. Data structures for source media and compositions are described in more detail below.