YCbCr, Y′CbCr, or Y Pb/Cb Pr/Cr, also written as YCBCR or Y′CBCR, is a family of color spaces used as a part of the color image pipeline in video and digital photography systems. Y′ is the luma component and CB and CR are the blue-difference and red-difference chroma components. Y′ (with prime) is distinguished from Y, which is luminance, meaning that light intensity is nonlinearly encoded based on gamma correctedRGB primaries.
Y′CbCr is not an absolute color space; rather, it is a way of encoding RGB information. The actual color displayed depends on the actual RGB primaries used to display the signal. Therefore a value expressed as Y′CbCr is predictable only if standard RGB primary chromaticities are used.
Rationale
Cathode ray tube displays are driven by red, green, and blue voltage signals, but these RGB signals are not efficient as a representation for storage and transmission, since they have a lot of redundancy.
YCbCr and Y′CbCr are a practical approximation to color processing and perceptual uniformity, where the primary colors corresponding roughly to red, green and blue are processed into perceptually meaningful information. By doing this, subsequent image/video processing, transmission and storage can do operations and introduce errors in perceptually meaningful ways. Y′CbCr is used to separate out a luma signal (Y′) that can be stored with high resolution or transmitted at high bandwidth, and two chroma components (CB and CR) that can be bandwidth-reduced, subsampled, compressed, or otherwise treated separately for improved system efficiency.
This computer science video compares the RGB colour model with the YCbCr colour model. It shows how both RGB and YCbCr can be visualised in three dimensional space, and how the grayscale relates to both colour models. The evolution of YCbCr from YUV is mentioned, along with the need for YCbCr as a means of encoding digital TV and video. The purpose of the luma component, Y, and the two chroma components, Cb and Cr, are explained. The key benefit of YCbCr as a colour model that separates the luminosity (brightness) of a pixel from the colour information is also explained. This makes conversion from RGB to YCbCr one of the key steps of the JPEG image compression algorithm.
Attribution: Clip of The Adventures Of Sir Lancelot. Usage: Public Domain Mark 1.0; From: https://archive.org/det...
published: 23 Nov 2019
YCbCr vs RGB
Its seems that YCbCr422 can keep the monitor refresh rate rather than RGB.
Of course it would rely on the hardware environment.
I'm using Toshiba 4K TV as monitor and tested the color format through Nvidia Control Panel.
published: 07 Mar 2022
4:4:4 vs. 4:2:2 vs. 4:2:0
What's the difference between 420, 422, and 444? What does 4:2:0, 4:2:2, and 4:4:4 mean? Do I need 420, 422, or 444 on my camera? Find all your answers here!
Get featured in videos, vote on what videos I should make next, or be the first to know about what will drop next at Patreon for $1/day or less! https://www.patreon.com/user?u=74052250
Affiliate Links:
If you want to try a free trial of the animation software I use, check it out here: https://vyond.grsm.io/yshr3hiha46n
When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, Vyond.
Feel free to check out my business website: https://www.magnumvp.com
or contact me at [email protected]
published: 07 May 2022
RGB vs YUV (YCbCr) color models (AKIO TV)
You're probably familiar with the RGB color model, but there are also other models out there, with the most common one being YUV (YCbCr).
(AKIO TV) MMXIX
published: 26 Apr 2019
YCbCr
YCbCr, Y′CbCr, or Y Pb/Cb Pr/Cr, also written as YCBCR or Y′CBCR, is a family of color spaces used as a part of the color image pipeline in video and digital photography systems. Y′ is the luma component and CB and CR are the blue-difference and red-difference chroma components. Y′ (with prime) is distinguished from Y, which is luminance, meaning that light intensity is nonlinearly encoded based on gamma corrected RGB primaries.
Y′CbCr is not an absolute color space; rather, it is a way of encoding RGB information. The actual color displayed depends on the actual RGB primaries used to display the signal. Therefore a value expressed as Y′CbCr is predictable only if standard RGB primary chromaticities are used.
This video is targeted to blind users.
Attribution:
Article text available und...
published: 11 Oct 2014
HDMI - RGB vs YCbCr 4:2:2 / 4:2:0 - It Really Doesn't Matter !
Ignore the 8bit info when YCbCr in 4:2:2 is displayed. This is a wrong info from the HDMI Port. HDTV Test proved already that the real Signal is 10bit in YCbCr 4:2:2.
In this Video, I compare RGB with YCbCr 4:2:2 and YCbCr 4:2:0. Please support my channel and like , share and subscribe. Thank You!
published: 13 Nov 2022
Image Formats part 2 RGB and YCbCr
Part 2 of my series on image formats and quality tradeoffs.
published: 23 Jan 2020
Split color channels - RGB, HSI, YCbCr, YUV, YIQ, YUW
This program splits the channel into several version.
There are many color channels for image processing such as RGB, HSI, YCbCr, YUV, YIQ, YUW.
You can download entire source code and report document(doc) from my blog but the report is written by korean (sorry).
http://feelmare.blogspot.com/2011/08/split-color-channels-rgb-hsi-ycbcr-yuv.html
이 프로그램은 bmp파일을 열어서 여러가지 채널로 분리하는 간단한 영상 처리 프로그램입니다.
색 채널 분리는 이미지 처리 책에서 쉽게 그 방법과 원리를 찾아 볼 수 있습니다.
예를 들어 RGB에서 YCbCr로 분리하는 방법은 아래 수식으로 가능합니다.
Y = 0.299*R + 0.587*G + 0.114*B
Cb = -0.16874*R + -0.33126*G + 0.5*B
Cr = 0.5*R + -0.41869*G - 0.08131*B
더 자세한 내용은 링크한 저의 전체 소스 코드를 첨부하세요.
압축 파일에는 한글로 된 보고서도 포함되어 있습니다.
http://feelmare.blogspot.com/2011/08/split-color-channels-rgb-hsi-ycbcr-yuv.html
published: 21 Aug 2011
【色彩管理】视频编码: YCbCr 422 420
published: 18 Aug 2020
YCbCr Color Space
Subscribe To My Channel https://www.youtube.com/@huseyin_ozdemir?sub_confirmation=1
Video Contents:
00:00 Introduction
00:55 RGB YCbCr Conversion Equations
03:46 RGB Color Space Inside YCbCr Color Space
05:06 Different Views of RGB and YCbCr Color Spaces
06:13 CbCr planes for Different Y Values
06:53 CbCr Planes Inside YCbCr Color Space
07:44 Conversion of an Image To YCbCr To Observe Channels
08:41 Python Code To Convert RGB To YCbCr
09:37 Advantage of Using YCbCr
* The purpose of using YCbCr
* When to use YCbCr
* RGB - YCbCr conversion equations
* RGB Color Space inside YCbCr Color Space
* Illustrations on transformed RGB Color Space
* CbCr Planes inside YCbCr Color Space
* Valid and nonvalid RGB coordinates
* Observing Y, Cb, Cr channels of an image
* Python code with OpenCV
All ima...
This computer science video compares the RGB colour model with the YCbCr colour model. It shows how both RGB and YCbCr can be visualised in three dimensional s...
This computer science video compares the RGB colour model with the YCbCr colour model. It shows how both RGB and YCbCr can be visualised in three dimensional space, and how the grayscale relates to both colour models. The evolution of YCbCr from YUV is mentioned, along with the need for YCbCr as a means of encoding digital TV and video. The purpose of the luma component, Y, and the two chroma components, Cb and Cr, are explained. The key benefit of YCbCr as a colour model that separates the luminosity (brightness) of a pixel from the colour information is also explained. This makes conversion from RGB to YCbCr one of the key steps of the JPEG image compression algorithm.
Attribution: Clip of The Adventures Of Sir Lancelot. Usage: Public Domain Mark 1.0; From: https://archive.org/details/TheAdventuresOfSirLancelotEp26
Attribution: Clip of video broadcast editing. By Joseph Redfield; From: https://www.pexels.com/video/people-works-on-a-broadcast-of-an-event-2890236/
This computer science video compares the RGB colour model with the YCbCr colour model. It shows how both RGB and YCbCr can be visualised in three dimensional space, and how the grayscale relates to both colour models. The evolution of YCbCr from YUV is mentioned, along with the need for YCbCr as a means of encoding digital TV and video. The purpose of the luma component, Y, and the two chroma components, Cb and Cr, are explained. The key benefit of YCbCr as a colour model that separates the luminosity (brightness) of a pixel from the colour information is also explained. This makes conversion from RGB to YCbCr one of the key steps of the JPEG image compression algorithm.
Attribution: Clip of The Adventures Of Sir Lancelot. Usage: Public Domain Mark 1.0; From: https://archive.org/details/TheAdventuresOfSirLancelotEp26
Attribution: Clip of video broadcast editing. By Joseph Redfield; From: https://www.pexels.com/video/people-works-on-a-broadcast-of-an-event-2890236/
Its seems that YCbCr422 can keep the monitor refresh rate rather than RGB.
Of course it would rely on the hardware environment.
I'm using Toshiba 4K TV as moni...
Its seems that YCbCr422 can keep the monitor refresh rate rather than RGB.
Of course it would rely on the hardware environment.
I'm using Toshiba 4K TV as monitor and tested the color format through Nvidia Control Panel.
Its seems that YCbCr422 can keep the monitor refresh rate rather than RGB.
Of course it would rely on the hardware environment.
I'm using Toshiba 4K TV as monitor and tested the color format through Nvidia Control Panel.
What's the difference between 420, 422, and 444? What does 4:2:0, 4:2:2, and 4:4:4 mean? Do I need 420, 422, or 444 on my camera? Find all your answers here!
...
What's the difference between 420, 422, and 444? What does 4:2:0, 4:2:2, and 4:4:4 mean? Do I need 420, 422, or 444 on my camera? Find all your answers here!
Get featured in videos, vote on what videos I should make next, or be the first to know about what will drop next at Patreon for $1/day or less! https://www.patreon.com/user?u=74052250
Affiliate Links:
If you want to try a free trial of the animation software I use, check it out here: https://vyond.grsm.io/yshr3hiha46n
When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, Vyond.
Feel free to check out my business website: https://www.magnumvp.com
or contact me at [email protected]
What's the difference between 420, 422, and 444? What does 4:2:0, 4:2:2, and 4:4:4 mean? Do I need 420, 422, or 444 on my camera? Find all your answers here!
Get featured in videos, vote on what videos I should make next, or be the first to know about what will drop next at Patreon for $1/day or less! https://www.patreon.com/user?u=74052250
Affiliate Links:
If you want to try a free trial of the animation software I use, check it out here: https://vyond.grsm.io/yshr3hiha46n
When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, Vyond.
Feel free to check out my business website: https://www.magnumvp.com
or contact me at [email protected]
You're probably familiar with the RGB color model, but there are also other models out there, with the most common one being YUV (YCbCr).
(AKIO TV) MMXIX
You're probably familiar with the RGB color model, but there are also other models out there, with the most common one being YUV (YCbCr).
(AKIO TV) MMXIX
You're probably familiar with the RGB color model, but there are also other models out there, with the most common one being YUV (YCbCr).
(AKIO TV) MMXIX
YCbCr, Y′CbCr, or Y Pb/Cb Pr/Cr, also written as YCBCR or Y′CBCR, is a family of color spaces used as a part of the color image pipeline in video and digital ph...
YCbCr, Y′CbCr, or Y Pb/Cb Pr/Cr, also written as YCBCR or Y′CBCR, is a family of color spaces used as a part of the color image pipeline in video and digital photography systems. Y′ is the luma component and CB and CR are the blue-difference and red-difference chroma components. Y′ (with prime) is distinguished from Y, which is luminance, meaning that light intensity is nonlinearly encoded based on gamma corrected RGB primaries.
Y′CbCr is not an absolute color space; rather, it is a way of encoding RGB information. The actual color displayed depends on the actual RGB primaries used to display the signal. Therefore a value expressed as Y′CbCr is predictable only if standard RGB primary chromaticities are used.
This video is targeted to blind users.
Attribution:
Article text available under CC-BY-SA
Creative Commons image source in video
YCbCr, Y′CbCr, or Y Pb/Cb Pr/Cr, also written as YCBCR or Y′CBCR, is a family of color spaces used as a part of the color image pipeline in video and digital photography systems. Y′ is the luma component and CB and CR are the blue-difference and red-difference chroma components. Y′ (with prime) is distinguished from Y, which is luminance, meaning that light intensity is nonlinearly encoded based on gamma corrected RGB primaries.
Y′CbCr is not an absolute color space; rather, it is a way of encoding RGB information. The actual color displayed depends on the actual RGB primaries used to display the signal. Therefore a value expressed as Y′CbCr is predictable only if standard RGB primary chromaticities are used.
This video is targeted to blind users.
Attribution:
Article text available under CC-BY-SA
Creative Commons image source in video
Ignore the 8bit info when YCbCr in 4:2:2 is displayed. This is a wrong info from the HDMI Port. HDTV Test proved already that the real Signal is 10bit in YCbCr ...
Ignore the 8bit info when YCbCr in 4:2:2 is displayed. This is a wrong info from the HDMI Port. HDTV Test proved already that the real Signal is 10bit in YCbCr 4:2:2.
In this Video, I compare RGB with YCbCr 4:2:2 and YCbCr 4:2:0. Please support my channel and like , share and subscribe. Thank You!
Ignore the 8bit info when YCbCr in 4:2:2 is displayed. This is a wrong info from the HDMI Port. HDTV Test proved already that the real Signal is 10bit in YCbCr 4:2:2.
In this Video, I compare RGB with YCbCr 4:2:2 and YCbCr 4:2:0. Please support my channel and like , share and subscribe. Thank You!
This program splits the channel into several version.
There are many color channels for image processing such as RGB, HSI, YCbCr, YUV, YIQ, YUW.
You can downl...
This program splits the channel into several version.
There are many color channels for image processing such as RGB, HSI, YCbCr, YUV, YIQ, YUW.
You can download entire source code and report document(doc) from my blog but the report is written by korean (sorry).
http://feelmare.blogspot.com/2011/08/split-color-channels-rgb-hsi-ycbcr-yuv.html
이 프로그램은 bmp파일을 열어서 여러가지 채널로 분리하는 간단한 영상 처리 프로그램입니다.
색 채널 분리는 이미지 처리 책에서 쉽게 그 방법과 원리를 찾아 볼 수 있습니다.
예를 들어 RGB에서 YCbCr로 분리하는 방법은 아래 수식으로 가능합니다.
Y = 0.299*R + 0.587*G + 0.114*B
Cb = -0.16874*R + -0.33126*G + 0.5*B
Cr = 0.5*R + -0.41869*G - 0.08131*B
더 자세한 내용은 링크한 저의 전체 소스 코드를 첨부하세요.
압축 파일에는 한글로 된 보고서도 포함되어 있습니다.
http://feelmare.blogspot.com/2011/08/split-color-channels-rgb-hsi-ycbcr-yuv.html
This program splits the channel into several version.
There are many color channels for image processing such as RGB, HSI, YCbCr, YUV, YIQ, YUW.
You can download entire source code and report document(doc) from my blog but the report is written by korean (sorry).
http://feelmare.blogspot.com/2011/08/split-color-channels-rgb-hsi-ycbcr-yuv.html
이 프로그램은 bmp파일을 열어서 여러가지 채널로 분리하는 간단한 영상 처리 프로그램입니다.
색 채널 분리는 이미지 처리 책에서 쉽게 그 방법과 원리를 찾아 볼 수 있습니다.
예를 들어 RGB에서 YCbCr로 분리하는 방법은 아래 수식으로 가능합니다.
Y = 0.299*R + 0.587*G + 0.114*B
Cb = -0.16874*R + -0.33126*G + 0.5*B
Cr = 0.5*R + -0.41869*G - 0.08131*B
더 자세한 내용은 링크한 저의 전체 소스 코드를 첨부하세요.
압축 파일에는 한글로 된 보고서도 포함되어 있습니다.
http://feelmare.blogspot.com/2011/08/split-color-channels-rgb-hsi-ycbcr-yuv.html
Subscribe To My Channel https://www.youtube.com/@huseyin_ozdemir?sub_confirmation=1
Video Contents:
00:00 Introduction
00:55 RGB YCbCr Conversion Equations
03:...
Subscribe To My Channel https://www.youtube.com/@huseyin_ozdemir?sub_confirmation=1
Video Contents:
00:00 Introduction
00:55 RGB YCbCr Conversion Equations
03:46 RGB Color Space Inside YCbCr Color Space
05:06 Different Views of RGB and YCbCr Color Spaces
06:13 CbCr planes for Different Y Values
06:53 CbCr Planes Inside YCbCr Color Space
07:44 Conversion of an Image To YCbCr To Observe Channels
08:41 Python Code To Convert RGB To YCbCr
09:37 Advantage of Using YCbCr
* The purpose of using YCbCr
* When to use YCbCr
* RGB - YCbCr conversion equations
* RGB Color Space inside YCbCr Color Space
* Illustrations on transformed RGB Color Space
* CbCr Planes inside YCbCr Color Space
* Valid and nonvalid RGB coordinates
* Observing Y, Cb, Cr channels of an image
* Python code with OpenCV
All images, animations and code in this video belong to me
#machinelearning #computervision
#ycbcr #deeplearning #ai
#grayscale #rgb2ycbcr #rgb2grayscale
#artificialintelligence #aitutorial #rgb2ycbcrpython
#convolutionalneuralnetwork #neuralnetwork
#convolutionalneuralnetworks #neuralnetworks
#imageprocessing #datascience
#computervisionwithhuseyinozdemir
Subscribe To My Channel https://www.youtube.com/@huseyin_ozdemir?sub_confirmation=1
Video Contents:
00:00 Introduction
00:55 RGB YCbCr Conversion Equations
03:46 RGB Color Space Inside YCbCr Color Space
05:06 Different Views of RGB and YCbCr Color Spaces
06:13 CbCr planes for Different Y Values
06:53 CbCr Planes Inside YCbCr Color Space
07:44 Conversion of an Image To YCbCr To Observe Channels
08:41 Python Code To Convert RGB To YCbCr
09:37 Advantage of Using YCbCr
* The purpose of using YCbCr
* When to use YCbCr
* RGB - YCbCr conversion equations
* RGB Color Space inside YCbCr Color Space
* Illustrations on transformed RGB Color Space
* CbCr Planes inside YCbCr Color Space
* Valid and nonvalid RGB coordinates
* Observing Y, Cb, Cr channels of an image
* Python code with OpenCV
All images, animations and code in this video belong to me
#machinelearning #computervision
#ycbcr #deeplearning #ai
#grayscale #rgb2ycbcr #rgb2grayscale
#artificialintelligence #aitutorial #rgb2ycbcrpython
#convolutionalneuralnetwork #neuralnetwork
#convolutionalneuralnetworks #neuralnetworks
#imageprocessing #datascience
#computervisionwithhuseyinozdemir
This computer science video compares the RGB colour model with the YCbCr colour model. It shows how both RGB and YCbCr can be visualised in three dimensional space, and how the grayscale relates to both colour models. The evolution of YCbCr from YUV is mentioned, along with the need for YCbCr as a means of encoding digital TV and video. The purpose of the luma component, Y, and the two chroma components, Cb and Cr, are explained. The key benefit of YCbCr as a colour model that separates the luminosity (brightness) of a pixel from the colour information is also explained. This makes conversion from RGB to YCbCr one of the key steps of the JPEG image compression algorithm.
Attribution: Clip of The Adventures Of Sir Lancelot. Usage: Public Domain Mark 1.0; From: https://archive.org/details/TheAdventuresOfSirLancelotEp26
Attribution: Clip of video broadcast editing. By Joseph Redfield; From: https://www.pexels.com/video/people-works-on-a-broadcast-of-an-event-2890236/
Its seems that YCbCr422 can keep the monitor refresh rate rather than RGB.
Of course it would rely on the hardware environment.
I'm using Toshiba 4K TV as monitor and tested the color format through Nvidia Control Panel.
What's the difference between 420, 422, and 444? What does 4:2:0, 4:2:2, and 4:4:4 mean? Do I need 420, 422, or 444 on my camera? Find all your answers here!
Get featured in videos, vote on what videos I should make next, or be the first to know about what will drop next at Patreon for $1/day or less! https://www.patreon.com/user?u=74052250
Affiliate Links:
If you want to try a free trial of the animation software I use, check it out here: https://vyond.grsm.io/yshr3hiha46n
When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, Vyond.
Feel free to check out my business website: https://www.magnumvp.com
or contact me at [email protected]
You're probably familiar with the RGB color model, but there are also other models out there, with the most common one being YUV (YCbCr).
(AKIO TV) MMXIX
YCbCr, Y′CbCr, or Y Pb/Cb Pr/Cr, also written as YCBCR or Y′CBCR, is a family of color spaces used as a part of the color image pipeline in video and digital photography systems. Y′ is the luma component and CB and CR are the blue-difference and red-difference chroma components. Y′ (with prime) is distinguished from Y, which is luminance, meaning that light intensity is nonlinearly encoded based on gamma corrected RGB primaries.
Y′CbCr is not an absolute color space; rather, it is a way of encoding RGB information. The actual color displayed depends on the actual RGB primaries used to display the signal. Therefore a value expressed as Y′CbCr is predictable only if standard RGB primary chromaticities are used.
This video is targeted to blind users.
Attribution:
Article text available under CC-BY-SA
Creative Commons image source in video
Ignore the 8bit info when YCbCr in 4:2:2 is displayed. This is a wrong info from the HDMI Port. HDTV Test proved already that the real Signal is 10bit in YCbCr 4:2:2.
In this Video, I compare RGB with YCbCr 4:2:2 and YCbCr 4:2:0. Please support my channel and like , share and subscribe. Thank You!
This program splits the channel into several version.
There are many color channels for image processing such as RGB, HSI, YCbCr, YUV, YIQ, YUW.
You can download entire source code and report document(doc) from my blog but the report is written by korean (sorry).
http://feelmare.blogspot.com/2011/08/split-color-channels-rgb-hsi-ycbcr-yuv.html
이 프로그램은 bmp파일을 열어서 여러가지 채널로 분리하는 간단한 영상 처리 프로그램입니다.
색 채널 분리는 이미지 처리 책에서 쉽게 그 방법과 원리를 찾아 볼 수 있습니다.
예를 들어 RGB에서 YCbCr로 분리하는 방법은 아래 수식으로 가능합니다.
Y = 0.299*R + 0.587*G + 0.114*B
Cb = -0.16874*R + -0.33126*G + 0.5*B
Cr = 0.5*R + -0.41869*G - 0.08131*B
더 자세한 내용은 링크한 저의 전체 소스 코드를 첨부하세요.
압축 파일에는 한글로 된 보고서도 포함되어 있습니다.
http://feelmare.blogspot.com/2011/08/split-color-channels-rgb-hsi-ycbcr-yuv.html
Subscribe To My Channel https://www.youtube.com/@huseyin_ozdemir?sub_confirmation=1
Video Contents:
00:00 Introduction
00:55 RGB YCbCr Conversion Equations
03:46 RGB Color Space Inside YCbCr Color Space
05:06 Different Views of RGB and YCbCr Color Spaces
06:13 CbCr planes for Different Y Values
06:53 CbCr Planes Inside YCbCr Color Space
07:44 Conversion of an Image To YCbCr To Observe Channels
08:41 Python Code To Convert RGB To YCbCr
09:37 Advantage of Using YCbCr
* The purpose of using YCbCr
* When to use YCbCr
* RGB - YCbCr conversion equations
* RGB Color Space inside YCbCr Color Space
* Illustrations on transformed RGB Color Space
* CbCr Planes inside YCbCr Color Space
* Valid and nonvalid RGB coordinates
* Observing Y, Cb, Cr channels of an image
* Python code with OpenCV
All images, animations and code in this video belong to me
#machinelearning #computervision
#ycbcr #deeplearning #ai
#grayscale #rgb2ycbcr #rgb2grayscale
#artificialintelligence #aitutorial #rgb2ycbcrpython
#convolutionalneuralnetwork #neuralnetwork
#convolutionalneuralnetworks #neuralnetworks
#imageprocessing #datascience
#computervisionwithhuseyinozdemir
YCbCr, Y′CbCr, or Y Pb/Cb Pr/Cr, also written as YCBCR or Y′CBCR, is a family of color spaces used as a part of the color image pipeline in video and digital photography systems. Y′ is the luma component and CB and CR are the blue-difference and red-difference chroma components. Y′ (with prime) is distinguished from Y, which is luminance, meaning that light intensity is nonlinearly encoded based on gamma correctedRGB primaries.
Y′CbCr is not an absolute color space; rather, it is a way of encoding RGB information. The actual color displayed depends on the actual RGB primaries used to display the signal. Therefore a value expressed as Y′CbCr is predictable only if standard RGB primary chromaticities are used.
Rationale
Cathode ray tube displays are driven by red, green, and blue voltage signals, but these RGB signals are not efficient as a representation for storage and transmission, since they have a lot of redundancy.
YCbCr and Y′CbCr are a practical approximation to color processing and perceptual uniformity, where the primary colors corresponding roughly to red, green and blue are processed into perceptually meaningful information. By doing this, subsequent image/video processing, transmission and storage can do operations and introduce errors in perceptually meaningful ways. Y′CbCr is used to separate out a luma signal (Y′) that can be stored with high resolution or transmitted at high bandwidth, and two chroma components (CB and CR) that can be bandwidth-reduced, subsampled, compressed, or otherwise treated separately for improved system efficiency.