How Video Works

CHAPTER 21

Test Signals, Displays, and Media Problems

Unlike program material, test signals are designed to assist in achieving precisely defined measurements in the video signal. They are used to determine whether a piece of equipment or system is working properly, to measure noise levels in the signal, chroma errors, errors that occur in the converging of the chroma and luminance signals, and to measure signal levels to ensure they meet proper standards. There is a multitude of test signals, each one designed to measure a specific aspect of the television signal.

Both the digital and analog domains make use of some of the same test signals. However, because analog and digital signals are prone to different types of errors, the way test signals ...