Apple Final Cut Pro 7 - Manual (Page 1299)

This chapter covers the following:
• RGB Color Model (p. 1299)
• Y
′
CBCR Color Model (p. 1300)
• Measuring Video Levels with the Final Cut Pro Video Scopes (p. 1304)
• Preventing Illegal Broadcast Levels (p. 1315)
• Displaying Excess Luma and Chroma Levels in the Viewer and Canvas (p. 1317)
• Using the Broadcast Safe Filter (p. 1318)
• Using the RGB Limit Filter (p. 1323)
• Working with Analog Video (p. 1325)
• Using Color Bars for Video Calibration (p. 1331)
Features such as the real-time video scopes and the Broadcast Safe filter help you precisely
analyze and control video levels to maintain broadcast standards.
Before you can effectively perform color correction, you need to understand the basics
of what makes up the image of a video file. Video and graphics files can represent color
information several ways. Traditionally, computer-generated video uses RGB color
encoding, while digital video systems use Y
′
C
B
C
R
(sometimes known as YUV video)
encoding.
RGB Color Model
In the retina of the eye, there are three kinds of color receptors, called cone cells. The three
kinds of cone cells are sensitive to the short, medium, and long wavelengths of visible
light, respectively. The RGB color model approximates the way human vision encodes
images by using three primary color channels: red, green, and blue. Emitted light sources
such as CRT monitors, flat-panel displays, and video projectors use the RGB color model,
as do image-capturing devices such as video cameras and computers.
1299
Measuring and Setting Video
Levels 78