Abstract: A multiple channel motion picture sound record is reproduced with selective ontrol of the cross-talk between channels due to film weave. Such control is effected by lateral offset of the respective sound sensors, and conserves limited available width of the sound record. Also, tracks at both edges of a multi-track record are modulated in like phase by a common sound channel to minimize certain effects of film weave.

Abstract: Improved electronic compositing procedures and apparatus are described, ed typically on the blue screen process and suitable for processing motion pictures of professional quality and the like. The invention provides compensation for color impurity in the backing illumination over a continuous range of effective transparencies of the foreground scene. Applicant's previous method for limiting the blue video component for the foreground scene to permit reproduction of light blue foreground objects is improved by a dual limitation criterion which simultaneously suppresses blue flare light from the backing reflected by foreground objects of selected colors, typically including grey scale and flesh tones.

Abstract: Sound is recorded on color motion picture film in the form of variations of ue rather than overall density, with inverse density variations of different color media of the film directly superposed. With three distinct color media it is possible in that manner to record two separate sound channels, the respective channels being hue modulated on distinct hue axes. Such hue modulated sound records are inherently virtually free from noise due to occlusions such as dirt and scratches on the film. Apparatus is disclosed for recording sound in the described manner and for reproducing sound from such records, including electronic means for reducing additional forms of noise. The inherent reduction of noise permits the normal sound track area of conventional films to accommodate several distinct tracks, each of which can carry two distinct sound channels or one sound channel and a control channel.