Digital Color and Imaging
In my previous post, I focused on Industrial Color Technology as used in Process Industries such as Paint, Plastics, Textiles, Paper, and Printing.
There are several useful links in the references section to color introduction which will be beneficial to people interested in digital colors and imaging.
On Light, Vision, Appearance, Color and Imaging
In this post, I have focused on another aspect of color technology as used in Digital Technology and Graphics Arts and Design Industry.
Devices for Digital Color and Imaging
- Inkjet and Laser Printers
- Displays on Desktop Computers and Mobile Devices
- Television
- Digital Cameras/Photography
- Digital Video
Color Models
Not all color models listed below are device independent.
They represent human vision. These are international standards of color measurement. They were developed at diffrent times and are refinements on older models to mimic human vision and visual perception.
Image Source: COLOR PART 1: CIE CHROMATICITY AND PERCEPTION
RGB VS CMY Color Models
Image Source: BASICS OF COLOR IMAGING
List of Color Models
- CIE x,y,Y
- CIEXYZ
- CIELAB
- CIELCH
- CIELUV
- RGB
- CMYK
- HSB
- HSV
- HSL
- HSI
- YUV
- YIQ
- YCbCr
- YPbPr
Color Models Classification
Image Source: UNDERSTANDING COLOR MODELS: A REVIEW
Uses of Color Models
Image Source: UNDERSTANDING COLOR MODELS: A REVIEW
Color Models Taxonomy
Image Source: UNDERSTANDING COLOR MODELS: A REVIEW
Image Source: COLOR IMAGES, COLOR SPACES AND COLOR IMAGE PROCESSING
Spot Colors Color Spaces
These color systems are used in Spot Printing in commercial printing applications.
- ANPA
- Colour Index International
- DIC
- PMS
- FOCOLTONE
- HKS
- Munsell
- NCS
- Pantone
- RAL
- TOYO
- Truematch
Image Source: A PRIMER TO COLORS IN DIGITAL DESIGN
Color Spaces
Are device dependent color models.
- Adobe RGB 1998
- sRGB
- Apple RGB
- ProPHOTO
- Wide Gamut RGB
- DCI-P3 or Display P3
- P3 D65
- P3 Theatrical
- EBU Tech. 3213-E (Supersedes PAL)
- oRGB
- ECI RGB V2
- ColorMatch RGB
- Rec 2020
- SWOP CMYK
- HDTV RGB
- NTSC RGB
- CIE RGB
- SGI RGB
- PAL/SECAM RGB
- SMPTE-240M RGB
- SMPTE-C RGB
- ACES RGB
- Rec. 709 (ITU-R BT. 709)
- Photo RGB
- DCI-P3Pro
- REC 209
- scRGB
- ROMM RGB
- Arri LogC
- RedWideGamutRGB
- Bruce RGB
- Ekta Space PS5
- Don RGB 4
- Beta RGB
- Best RGB
- Max RGB
- Xtreme RGB
- Ma RGBta
List of Color Spaces available in PhotoShop
Image Source: WHICH IS THE BEST COLOR SPACE FOR PHOTOGRAPHY: SRGB OR ADOBE RGB?
List of Color Spaces used in Videos/Cinema
Image Source: COMMON RGB COLOR SPACES
Color Gamut
Is range of color. Defines boundaries of color space. Number of Hues will be higher in a larger color gamut color space.
A color gamut is the defining a range of chromaticities—essentially a set of possible hues and their respective maximum saturations.
Image Source: UNDERSTANDING COLOR SPACE
Image Source: Beginner’s Guide to Color Space: RGB, CMYK, and Pantone
Color Management
Color spaces are used in
- Capture of images, videos and Cinema
- Editing and Processing of Images and Videos
- Visual Displays on Computer Monitors, Phone and Tablet Displays, Digital Camera Displays, Digital Video Displays, Television, Cinema Screens, and LCD screens on Auto and Home appliances.
- Printing of Images on Ink Jet printers, Laser printers, Screen Printing, Offset Printing etc.
Flows of Images from
- Capture to Editing
- Editing to Viewing on Media Devices
- Editing to Printing on Media
- Editing to Storage on Media Devices
Image Source: COLOR SPACE
Color Spaces used for different stages of the process
- Capture – For Stills – Adobe RGB, sRGB; For Video -YUV
- Editing – ProPhoto, Adobe RGB, sRGB, CIEXYZ, YUV
- Viewing – sRGB
- Printing – CMYK
- Storage – sRGB, Adobe RGB, YUV, CMYK
Color Profiles
Color profiles define the specific color space (e.g. Adobe RGB) of a document or device. The terms color profile and color space are often used interchangeably.
Image Source: Digital Color Workflows and the
HP DreamColor LP2480zx Professional LCD Display
Please see the link below to learn about embedded color profiles. Since Color spaces are different, the tagged color profile is required for uniformity of image across different color spaces.
Color Filters
- Bayer Array
- Foveon X3
Source: COLOR FILTER ARRAY/Wikipedia
Color filters are needed because the typical photosensors detect light intensity with little or no wavelength specificity, and therefore cannot separate color information.[1] Since sensors are made of semiconductors they obey solid-state physics.
The color filters filter the light by wavelength range, such that the separate filtered intensities include information about the color of light. For example, the Bayer filter (shown to the right) gives information about the intensity of light in red, green, and blue (RGB) wavelength regions. The raw image data captured by the image sensor is then converted to a full-color image (with intensities of all three primary colors represented at each pixel) by a demosaicing algorithm which is tailored for each type of color filter. The spectral transmittance of the CFA elements along with the demosaicing algorithm jointly determine the color rendition.[2] The sensor’s passband quantum efficiency and span of the CFA’s spectral responses are typically wider than the visible spectrum, thus all visible colors can be distinguished. The responses of the filters do not generally correspond to the CIE color matching functions,[3] so a color translation is required to convert the tristimulus values into a common, absolute color space.[4]
Source: COLOR FILTER ARRAY/Wikipedia
Color BIT Depth
Defines details of a color image. More bit depth means more data storage per pixel of screen.
Color Gamut and Bit Depth defines color of an image.
What color Gamut was used and what bit depth was used in creating, editing, viewing, printing, and storing of an image?
Source: Human Vision and Digital Color Perception
The bit depth is what determines the color information of a digital image. The more bits stored in a pixel, the more information is stored and the greater the detail in color. The following is a guide of how many colors can be represented based on the number of bits.
1 Bit — 2 colors (Monochrome)
8 Bit — 256 colors (Low Color)
16 Bit — 65536 colors (High Color)
24 Bit — 16777216 colors (True Color)
Image Source: INTRODUCTION TO BASIC MEASURES OF A DIGITAL IMAGE FOR PICTORIAL COLLECTIONS
Rendering Intent
Image Source: A Breakdown Of Color Spaces | You Really Should Have A Grasp On This
Image Source: Choosing a color space: sRGB, Adobe RGB and ProPhoto RGB
Image Format during Image Capture
- RAW
- JPEG
- JPEG2000
Using Color Filter Array, the color data is captured in RAW form. It then is converted to JPEG image file format.
Image Source: UNDERSTANDING DIGITAL RAW CAPTURE
Process Flows In Digital Color Imaging System
Image Source: SYSTEM OPTIMIZATION IN DIGITAL COLOR IMAGING
Digital Color Terminology
Image Source:
My Related Posts
On Light, Vision, Appearance, Color and Imaging
Key Sources of Research
Basics of Color Imaging
Yao Wang
Introduction to Color Imaging Science
HSIEN-CHE LEE
Digital Color Imaging
Gaurav Sharma, Member, IEEE, and H. Joel Trussell, Fellow, IEEE
Digital Color Imaging Handbook
Edited By Gaurav Sharma, Gaurav Sharma, Raja Bala
https://www.taylorfrancis.com/books/e/9781315220086/chapters/10.1201/9781420041484-1
HUMAN VISION AND DIGITAL COLOR PERCEPTION
Vince Tabora
HD Pro Blog
Medium.com
Understanding Chroma And Luminance In Digital Imaging
Vince Tabora
HD PRO
Medium.com
THE DIFFERENCE BETWEEN CMYK AND RGB IN DIGITAL PRINTING
Some Common RGB Working Space Matrices
http://brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
Color Part 1:
CIE Chromaticity and Perception
by Roger N. Clark
https://clarkvision.com/articles/color-cie-chromaticity-and-perception/
A Primer to Colors in Digital Design
Archit Jha
https://uxdesign.cc/a-primer-to-colors-in-digital-design-7d16bb33399e
Digital Color Workflows and the
HP DreamColor LP2480zx Professional LCD Display
RGB color space profiles
http://www.hutchcolor.com/profiles.html#freeRGBspaces
Video Colour Color Space for photographers
http://www.jamesmilnersmyth.com/video-colour-color-space-for-photographers/
Understanding Color Space
https://stephaniebryanphoto.com/myblog/understanding-color-space
Choosing a color space: sRGB, Adobe RGB and ProPhoto RGB
Information on Color Spaces and Rendering Intent
Canon
Understanding Color Models Used in Digital Image Processing
https://www.allaboutcircuits.com/technical-articleUnderstanding Color Models Used in Digital Image Processings/understanding-color-models-used-in-digital-image-processing/
Which is the Best Color Space for Photography: sRGB or Adobe RGB?
https://contrastly.com/which-is-the-best-color-space-for-photography-srgb-or-adobe-rgb/
How to Choose the Right Video Color Space
http://www.cinematiccolor.com/
Color Models
http://cs.brown.edu/courses/cs092/VA10/HTML/ColorModels.html
Color Space Mismatches
Colour Space Conversions
Adrian Ford (ajoec1@wmin.ac.uk <defunct>) and Alan Roberts (Alan.Roberts@rd.bbc.co.uk).
August 11, 1998(a)
UNDERSTANDING COLOR SPACES
Unraval
https://www.unravel.com.au/understanding-color-spaces
ColorPerfect, ColorNeg et al. and RGB / grayscale working spaces
https://www.colorperfect.com/working_spaces.html?lang=en
Color Space Names
Apple
https://developer.apple.com/documentation/coregraphics/cgcolorspace/color_space_names
History of the Very Odd sRGB Color Space
https://ninedegreesbelow.com/photography/srgb-history.html
color images, color spaces and color image processing
Ole-Johan Skrede 08.03.2017
INF2310 – Digital Image Processing
Department of Informatics
The Faculty of Mathematics and Natural Sciences University of Oslo
The Reversibility of Six Geometric Color Spaces
Tian-YuanShih
A Review of RGB Color Spaces
Beginner’s Guide to Color Space: RGB, CMYK, and Pantone
Color spaces, profiles and color management explained
https://lifeafterphotoshop.com/color-spaces-profiles-and-color-management-explained/
color space
PC Magazine
https://www.pcmag.com/encyclopedia/term/color-space
Digital-Image Color Spaces
Jeffrey Friedl’s Blog
Color Spaces and Digital Imaging
Higham, Nicholas J. 2015
The Essential Guide to Color Spaces
Mathematical Representation of Color Spaces and Its Role in Communication Systems
Riyadh M. Al-saleem ,1 Baraa M. Al-Hilali ,2 and Izz K. Abboud
https://www.hindawi.com/journals/jam/2020/4640175/
Color Spaces and Color Profiles
https://www.dpbestflow.org/color/color-space-and-color-profiles
Good One
Commercial Printing
https://www.dpbestflow.org/color/commercial-printing
https://www.dpbestflow.org/links/31
Color Management Overview
https://www.dpbestflow.org/node/247
Describing, Specifying, and Using Digital Digital Color Space
NOVEMBER 18, 2002
https://www.screenweb.com/content/describing-specifying-and-using-digital-digital-color-space
Introduction to Light, Color and Color Space
https://www.scratchapixel.com/lessons/digital-imaging/colors/color-space
The Color Space Conundrum
https://theasc.com/magazine/jan05/conundrum/index.html
A Breakdown Of Color Spaces | You Really Should Have A Grasp On This
A Standard Default Color Space for the Internet – sRGB
Michael Stokes (Hewlett-Packard), Matthew Anderson (Microsoft),
Srinivasan Chandrasekar (Microsoft), Ricardo Motta (Hewlett-Packard)
Version 1.10, November 5, 1996
https://www.w3.org/Graphics/Color/sRGB.html
Color Models
https://scc.ustc.edu.cn/zlsc/sugon/intel/ipp/ipp_manual/IPPI/ippi_ch6/ch6_color_models.htm
COLOR SCIENCE AND COLOR APPEARANCE MODELS FOR CG, HDTV, AND D-CINEMA
Authors:
Charles A Poynton
Garrett M Johnson
Publication: SIGGRAPH ’04: ACM SIGGRAPH 2004 Course NotesAugust 2004
Color in Information Display Principles, Perception, and Models
Maureen C. Stone
StoneSoup Consulting
Course 20 SIGGRAPH 2004
oRGB: A Practical Opponent Color Space for Computer Graphics
Margarita Bratkova∗ Solomon Boulos† Peter Shirley‡ University of Utah
Color in Science, Art and Industry: The Inter-Society Color Council 75th Anniversary CD
ISCC
Image Processing 101
Color Theory Color Models
http://www.pengadprinting.com/content/color-theory-part-ii-types-color-and-uses-0
Color Models (RGB vs CMYK)
Understanding Color Models: A Review
1 Noor A. Ibraheem, 2 Mokhtar M. Hasan, 3 Rafiqul Z. Khan, 4 Pramod K. Mishra
1 Department of Computer Science, Faculty of Science, Aligarh Muslim University, Uttar Pradesh, India
Color Theory
Colorotate
RGB vs HSB vs HSL - Demystified
Anagh Sharma
https://www.anaghsharma.com/blog/rgb-vs-hsb-vs-hsl-demystified/
System Optimization in Digital Color Imaging
Understanding and exploiting interactions
Raja Bala and Gaurav Sharma
IEEE Signal Processing Magazine · February 2005
Digital image processing
Gonzalez and Woods,
2nd edition, Prentice Hall, 2002
Which Color Space Should You Use When?
https://havecamerawilltravel.com/photographer/color-profiles/
DIGITAL IMAGING AND PHOTOGRAPHY
On Line Course
University of Delaware
https://www.eecis.udel.edu/~arce/courses/digitalimgproc/
Introduction to Basic Measures of a Digital Image for Pictorial Collections
Kit A. Peterson, Digital Conversion Specialist, June 2005
Prints & Photographs Division, Library of Congress, Washington, D.C. 20540-4730
Color spaces and gamut
Published on April 15, 2015 | Updated on October 31, 2019
https://www.color-management-guide.com/color-spaces.html
COLOR IN DIGITAL CINEMA
Color Spaces
http://www.updig.org/guidelines/ph_color_spaces.html
https://danpgomez.com/tbl/2016/3/29/whats-the-difference-between-a-color-space-and-a-color-profile
Review and evaluation of color spaces for image/video compression
Samruddhi Y. Kahu1 | Rajesh B. Raut2 | Kishor M. Bhurchandi
Color Res Appl. 2019;44:8–33.
Color filter array
https://en.wikipedia.org/wiki/Color_filter_array#List_of_color_filter_arrays
Eyeing the Camera: into the Next Century
Richard F. Lyon and Paul M. Hubel
Foveon, Inc.
Santa Clara, California, USA
Color Filter Arrays: Design and Performance Analysis
Rastislav Lukac, Member, IEEE, and Konstantinos N. Plataniotis, Senior Member, IEEE
IEEE Transactions on Consumer Electronics, Vol. 51, No. 4, NOVEMBER 2005
Introduction to Bayer Filters
https://www.arrow.com/en/research-and-events/articles/introduction-to-bayer-filters
DIGITAL CAMERA SENSORS
https://www.cambridgeincolour.com/tutorials/camera-sensors.htm
https://www.cambridgeincolour.com
Rethinking Color Cameras
Ayan Chakrabarti
William T. Freeman
Todd Zickler
IEEE 2014
Color Filter Arrays for Quanta Image Sensors
Omar A. Elgendy, Student Member, IEEE and Stanley H. Chan, Senior Member, IEEE
Quad Bayer sensors: what they are and what they are not
https://www.gsmarena.com/quad_bayer_sensors_explained-news-37459.php
Image sensor format
https://en.wikipedia.org/wiki/Image_sensor_format
Image file formats
https://en.wikipedia.org/wiki/Image_file_formats
Understanding Digital Raw Capture
Adobe
Why Every Editor, Colorist, and VFX Artist Needs to Understand ACES
Ben Bailey 2019
Common RGB Color Spaces
https://nick-shaw.github.io/cinematiccolor/common-rgb-color-spaces.html
Viewpoints which Matter 
9 thoughts on “Digital Color and Imaging”