What does the word "Chroma" actually mean? at DVinfo.net

David Delaney · August 14th, 2007, 09:13 AM

Does the word CHROMA refer to just colour when it deals with video?

Frank Simpson · August 14th, 2007, 09:48 AM

chroma |ˈkrōmə| noun purity or intensity of color.

ORIGIN late 19th cent.: from Greek khrōma ‘color.’

Glenn Chan · August 14th, 2007, 09:49 AM

In video systems chroma is the part of the signal that represents color; it's the color difference components of a video signal. You can get the numbers in a book like Charles Poynton's. Color and luminance is not separated perfectly... the wikipedia entry on chroma subsampling should have links to that information.

2- In the Munsell color system, chroma refers to the purity/saturation of a color. It is a slightly different concept. In video no one really talks about that color specification system.

3- There's a difference between chromaticity and chrominance (chroma is similar to chrominance)... the distinction of which is important when reading vectorscopes. Both refer to color. If you for example change the exposure on a camera, chrominance will change but chromaticity will stay the same. You can think of chrominance like "colorful light energy" that adds colorfulness to light... so if you change exposure, the overall energy changes and therefore that's why chrominance changes.

Intuitively when you think about color, chromaticity usually makes more sense. In some cases the distinction is not important.

Dean Sensui · August 14th, 2007, 02:36 PM

You guys are smart! I thought "chroma" was all the shiny silver stuff on Italian sportscars!

:-)

Paul V Doherty · August 15th, 2007, 11:00 AM

Chroma, pffft!

The only thing that counts is progressive scan, baby ;)

August 14th, 2007, 09:13 AM	#1
David Delaney Trustee Join Date: Feb 2006 Location: Niagara Ontario Canada Posts: 1,121	What does the word "Chroma" actually mean? Does the word CHROMA refer to just colour when it deals with video?

August 14th, 2007, 02:36 PM	#4
Dean Sensui Inner Circle Join Date: Oct 2001 Location: Honolulu, HI Posts: 2,054	You guys are smart! I thought "chroma" was all the shiny silver stuff on Italian sportscars! :-) __________________ Dean Sensui Exec Producer, Hawaii Goes Fishing

August 14th, 2007, 09:48 AM	#2
Frank Simpson Major Player Join Date: Jun 2007 Location: Bozeman, MT Posts: 217	chroma \|ˈkrōmə\| noun purity or intensity of color. ORIGIN late 19th cent.: from Greek khrōma ‘color.’

August 14th, 2007, 09:49 AM	#3
Glenn Chan Inner Circle Join Date: Jun 2003 Location: Toronto, Canada Posts: 4,750	In video systems chroma is the part of the signal that represents color; it's the color difference components of a video signal. You can get the numbers in a book like Charles Poynton's. Color and luminance is not separated perfectly... the wikipedia entry on chroma subsampling should have links to that information. 2- In the Munsell color system, chroma refers to the purity/saturation of a color. It is a slightly different concept. In video no one really talks about that color specification system. 3- There's a difference between chromaticity and chrominance (chroma is similar to chrominance)... the distinction of which is important when reading vectorscopes. Both refer to color. If you for example change the exposure on a camera, chrominance will change but chromaticity will stay the same. You can think of chrominance like "colorful light energy" that adds colorfulness to light... so if you change exposure, the overall energy changes and therefore that's why chrominance changes. Intuitively when you think about color, chromaticity usually makes more sense. In some cases the distinction is not important.

August 15th, 2007, 11:00 AM	#5
Paul V Doherty Regular Crew Join Date: Aug 2006 Location: USA Posts: 64	Chroma, pffft! The only thing that counts is progressive scan, baby ;)