ISF Video Standards & Signal Processing 4

Question 1

What is the function of a comb filter in analog video processing?

Accepted Answer

To separate the luma (Y) and chroma (C) components of a composite signal

Answer

A comb filter exploits the phase relationship between luma and chroma in composite video to separate them with minimal cross-contamination (cross-color and dot crawl).

Question 2

What does EOTF stand for, and what does it describe?

Accepted Answer

Electro-Optical Transfer Function; the mapping from signal code values to display light output

Answer

EOTF (Electro-Optical Transfer Function) describes how a display device converts electrical signal values into emitted light, the inverse of the OETF applied at capture.

Question 3

In a vectorscope display, what does a dot plotted at the center of the graticule indicate?

Accepted Answer

The signal has no chroma—it is neutral (black, gray, or white)

Answer

A vectorscope plots chroma as a dot whose angle represents hue and whose distance from center represents saturation; a dot at center means zero saturation (achromatic).

Question 4

Which color space is defined by the ITU-R BT.709 standard and is the reference for HDTV production?

Accepted Answer

A D65 white point with specific red, green, and blue primaries and a gamma of approximately 2.4

Answer

BT.709 specifies R/G/B primaries, a D65 white point, and an OETF with an effective display gamma near 2.4, serving as the standard for HDTV and most streaming content.

Question 5

What artifact is caused by incorrect deinterlacing when converting interlaced video to progressive?

Accepted Answer

Combing, where horizontal lines from two different fields appear at the same time causing jagged edges on moving objects

Answer

Combing occurs when a naive deinterlacer blends both fields of a frame containing motion, producing a comb-like edge artifact on moving objects.

(ISF) Imaging Science Foundation Certification Practice Test

(ISF) Imaging Science Foundation Certification Practice Test

ISF Video Standards & Signal Processing 4