The Digital Fact Book - Quantel

KeyingThe process of selectively overlaying an area of one picture (or clip) onto another. If theswitch between the overlaid and background pictures is simply ‘hard’ this can lead to jaggededges of the overlaid, or keyed, pictures. They are usually subjected to further processingto produce ramped, slightly soft, key edges to give a cleaner, more convincing, result.The whole technology of deriving key signals from image data and the color correctionsapplied to keyed image edges, has greatly expanded through the use of digital technology,so that many operations may be used together, e.g. softening the key, color correctingkey spill areas, and much more.See also: Chroma keying, Digital keying, Linear keyingKeystoning (Stereoscopic)The result arising when the film plane in a camera or projector is not parallel to the viewor screen, leading to a trapeze shape. On a stereoscopic image, where the camerasare ‘toed-in’ so that the object of interest coincides when viewed, there can be somemismatching of the outlines or borders of the two images. Techniques like corner pinningcan be used to help correct this.KLKLVKLV is a data encoding protocol (SMPTE 336M). The Key is a unique, registered sequenceof bits that defines the type of content that is coming (video, audio, EDL, etc) and Length– number of bytes ahead of Value, the content ‘payload’ itself. Compliance to KLV meansthat a wider range of equipment and applications can understand each other’s files.See also: AAF, MXFLADLaboratory Aim Density is a quality control method to maintain consistency in film prints.To aid in color timing, original negatives are timed relative to a LAD Control Film whichincludes reference patches and a figure of a girl (Marcie). There are differing LAD valuesfor each type of print or duplication film that the original will be printed on.117