Figure 01: sRGB lin-lin
Figure 02: sRGB log-lin
Color Management (RGB)
2022 © MediaTechnoLogicConsult | www.mtlc.eu/dam | author: Rudolf Eyberg | version: 2022-11-25 00:12 CETThis is a collection of information about color management. This knowledge is important for taking, creating, editing, displaying and printing digital images with defined and best possible colors.
What is a color space?
Please have a look on this Wikipeda page:
What is the sRGB color space?
This is the "Standard Red-Green-Blue" (sRGB) color space, as defined in the year 1999 in the international standard IEC 61996-2-1:1999. This standard was created for the defined processing of analogue signals between cameras and displays, at this time cathode ray tubes (CRT). But the sRGB standard is still valid and used for digital signals between digital cameras and computer monitors and projectors. And of course for all kind of digital image files coding like JPG, PNG and a lot of other files.
For further information, please have a look on this Wikipedia web page:
Have you every stumbled over the term "Gamma"?
Have you ever wondered why different gamma values 2.2 and 2.4 are published and used?
Have you ever wondered why 50 % white (gray) is not corresponding to 8 bit RGB value of 128 (= 50% of 256)?
You will find some answers and detailed explanation with descriptive graphics on this website! Of course a lot of good other websites do give already answers about such questions. But some only with the estimation of gamma 2.2 in simple formulas without any details. To my humble opinion the best website is from Eric Brasseur (see Chapter "References").
Due to the fact, that most of the relevant information is explained quite perfectly with good image examples by Eric, there is no need for me to repeat this. My intention is to provide additional information:
In short, the reason for nonlinear encoding is the human perception of all physical stimulus including audio and light.
With nonlinear digital encoding the need for number of bits is reduced drastically. In audio and photo coding with linear coding about 11 bit are required for good quality. But with nonlinear coding only 8 bit are required. That is a data reduction of factor eight = 8 = 2^2 = 2x2x2.
Please note, that nonlinear encoding is not new and not used only for digital photography with JPG, PNG and other image file formats. Nonlinear encoding is defined and used since a very long time also for analog transmission of image signals and telephony audio signals.
This chapter is still under construction!
But I like to publish already today some relevant graphics with sRGB transfer function.
These charts are dedicated especially to Eric Brasseur and Aurelien Pierre (see Chapter "References").
Thank you very much Eric for Gamma and thank you Aurelien for Darktable with Filmic RGB.
Detailed explanations of the following figures will be added here soon.
Important Remark: Log-Log axis has the advantage, that all exponential functions are easy to identify and draw, because they always are resulting in straight lines.
Thank you for feedback, if you have already now comments or corrections.
Please click on "Figure ##" to enlarge to full screen in new tab!
Please note, that the graphic files are in scalable vector format (SVG), which is scalable without loss.
| Figure 01: sRGB lin-lin |
Figure 02: sRGB log-lin |
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 Figure 03: sRGB lin-lin (with detail of Figure 01) |
 Figure 04: sRGB log-log |
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Please click on "Figure ##" to enlarge to full screen in new tab!
What kind of software is relevant for color management and content on this page?
(â–· All links in this chapter are external!)
This chapter contains carefully selected and only very good references to other websites.
(â–· All links in this chapter are external!)
History of major modifications on this web page:
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