Digital Cinema

[digital_cinema.pdf]

Digital Cinema• In March 2002, seven studios—Disney, Fox, MGM,Paramount, Sony Pictures Entertainment, Universal, andWarner Brothers Studios—established Digital CinemaInitiatives, in Los Angeles, to create a specification for digitalCinema: http://www.dcimovies.comImage resolution: minimum 2048 by 1080 pixels (called 2K;not exactly 16:9);upgradable to double resolution, (4096x2160, called 4K).Pixel depth: 36 bit/pixel (i.e. 12 bits per color)Fps: 24 or 48

Digital Cinema

A digital projection setup costs more (~ 100K$ instead of ~ 35K$), but - copies (on hard drives) for distribution cost much less than films- film quality degrades from copy to copy-of-copy- film quality starts degrading after a dozen showings (grease, scratches…)

Compression is needed:- ~ 6000 TB during editing- a few TB final uncompressed movie

Digital Cinema

Digital CinemaMPEG2 gives motion artifacts—the appearance of discontinuity or jerkiness in action scenes- rarely noticeable on a television screen but all too apparent on a large screenJPEG 2000 is used; it compresses whole frames as if each were a separate picture, which in fact each is. Final size ~ 300 GBSound: data size is negligible -> uncompressed CD-quality audio

Delivery (from the studios to the theaters)?- Truck (slow; hard disk are delicate…)- Fiber optics (secure; not available in some rural areas)- Satellite

Digital Cinema

The projector is normally based on DLP chips, a technology also used in high-end home projection TVs. DLP chips modulate light by bouncing it off arrays micromirrors

Digital Cinema: 3-D• In the past: two ways1. displaying two views of the image—one for the right eye, one for the left—using colored filters; the moviegoer wears glasses with a red filter in one lens and a blue filter in the other.2. Using polarized light; moviegoers wear glasses, in this case with lenses of different polarization.• In digital cinema- as in 2. above- with active glasses, in which each lens is a liquid-crystal shutter. An infrared signal sent from the projector tells the shutters when to switch to direct the image to the appropriate eye. No polarized light or color filter is necessary