Crestron C2N-DVP4DI Reference Manual page 99

Crestron C2N-DVP4DI
Reference Guide – DOC. 6177A
Progressive Scan – All Lines Displayed in 1/60
Line 1
Line 2
Last
Line
The DI in C2N-DVP4DI stands for de-interlacing. De-interlacing is the process by
which interlaced video is converted to progressively scanned video.
Interlaced and Progressive (de-interlaced) Scans of Objects in Motion
Motion
Alternate Line Displacment
in Interlaced Scan
Some de-interlacers simply rearrange fields by creating an even-line output frame
and an odd-line output frame every 60th of a second. Any motion occurring in the
time between the odd and even fields results in undesirable motion artifacts.
In another de-interlacer scheme, each of the odd and even fields is scaled up to the
entire frame size. The de-interlacer interpolates between the existing lines, reducing
motion artifacts but significantly reducing vertical resolution.
Motion adaptive de-interlacing applies an algorithm that compares subsequent
frames, reducing the vertical resolution of only the portion of the image that has
moved.
Line doublers are designed to take advantage of the 3:2 pulldown technique used to
transfer film to video. Film is recorded at 24 frames per second. To match speeds
with video scanning (60 frames per second), the first film frame is captured onto
three video fields (even, odd, and even) then the second film frame is captured onto
two video fields (odd and even). This creates ten interlaced video fields for every
four film frames.
An advanced line doubler de-interlacer (as in the C2N-DVP4DI) examines a series
of frames, detects the sequence and determines the pre-video film source. It then
Digital Video Processor
th
of a Second
Motion
Progressive Scan
Digital Video Processor: C2N- DVP4DI • 95