Image Processing Reference
In-Depth Information
The width and height in the table above are quoted in pixels.
Cinerama simultaneously projects three pictures that must be carefully synchro-
nized. Stitching these together digitally will yield a better result than scanning an
optically combined sub-master. The optical combination process results in two
lighter bands down the screen where the segments join.
Normal TV aspect ratio of 4:3 can be represented as 1.33:1 to compare it with the
above film formats.
Wide-screen TV aspect ratio of 16:9 can be represented as 1.78:1 to compare it with
the above film formats.
Maximum practical scanning resolution is assumed to be 115 pixels per mm based
on published details of an 8K scanning system for IMAX format. This equates to
2921 pixels per inch. Scanning resolutions actually vary widely according to film
size, grain size, and the age of the stock being scanned. Film scanners typically
operate at 2K, 4K, and 6K nominal resolution across the frame, with the vertical res-
olution depending on the aspect ratio.
Although the computations for bit rate are based on 24 frames per second (fps),
consumer film is also used at 18 fps to conserve footage and increase running times.
The bit rate per second and per hour is for uncompressed data scanned at the high-
est practical resolution.
The bit rates for Pathé 9.5 are based on calculations for monochrome pictures. Very
little color stock (if any) was available when this format was popular in the first half
of the 20th century.
Authoritative figures for the sound synchronization offset and the audio band-
width are not available at this time.
More information is available at the Film Center web site.
Film Center:
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