Introduction to Color Management for Film and TV

Introduction to Color Management for Film and TV

Igor Riđanović

Why color manage in food industry?

Why color manage in retail?

common source

multiple display devices

Why color manage in media?

correct color interpretation

incorrect color interpretation

Why color manage in post?

Why color manage in post?

What is color management?



Perceptually consistent color across a range of devices



Consistent color within a pipeline



Interoperability

Why is color management important in film and TV?

Brand identity  Protects integrity of creative intent 



Maintains suspension of disbelief

right

wrong

The nature of light and color

The nature of light and color

Objects and living beings have no color  Light energy absorption, reflection and transmission 

3D model Copyright © 2003-2013 Andrew Kator & Jennifer Legaz

How do we see light and color?

Rods see low light and no color  Three type of cones can see color 



Near logarithmic response to luminance

HansWerner Hunzik

er

How do we see light and color?

S, M and L cones

How do we see light and color? perceived brightness

perceived brightness

linear light intensity

Wolphram|Alpha

doubling light intensity

Additive and subtractive color mixing

Pko

Cantus

Color model and color space

Color model—an abstract primary color mixing principle  Color space—specific values for the primaries 



Color gamut—unambiguous color set defined by the primaries

CIE XYZ(1931) color space

CIE xy chromaticity diagram

sRGB color space

PAR

Color space classification

Device independent (example: CIE XYZ)  Device dependent (example: Rec. 709) 

Device dependent color

Examples:  Traditional CMYK press 

Analog and Digital TV

Device dependent color—numerical representation

In RGB color model each pixel is represented by the additive mix of its three channels (R + B + G) R 205 G 012 B 005

R 000 G 000 B 000

R 255 G 255 B 255

Device dependent color—numerical representation

Bit depth determines color precision

1 bit: fax

8 bit: grayscale

8 bit per channel: truecolor

Device dependent color—numerical representation

A bit is a binary numeral representing either “0” or “1” 1 bit: 2 levels 2 bit: 4 levels 10 bit: 1024 levels

Device dependent color—numerical representation

Values are intrinsically tied to the device

R 255 G 255 B 000

R 255 G 255 B 000

sRGB color space (computer monitor)

mystery color space (some handheld device)

Device dependent color

R 205 G 012 B 005 R 205 G 012 B 005

device 1

source device R 205 G 012 B 005 device 2

Device dependent color

R 205 G 012 B 005 source device R? G? B? device 2

Device dependent color

CMS R 205 G 012 B 005 source device R 212 G 008 B 010 device 2

Device dependent color

Color management: Typically translates color values from one device dependent color space to another device dependent color space with respect to gamut, gamma and dynamic range

Device dependent color—gamut

Rec. 2020 vs. Rec. 709 color gamut

GrandDrake

Device dependent color—gamut

Rec. 709 vs. DCI-P3 3D color gamut

Device dependent color—gamma

linear gamma

2.2 gamma

Wolfram|Alpha

Device dependent color—dynamic range

higher dynamic range lower dynamic range

original

gamma mismatch

gamut mismatch

reduced dynamic range

Case Study: Black and White TV (simplified) subject

camera

video

TV set OTA broadcast

Traditional TV color management

Single input, single output TV camera

editorial

TV monitor γ = 2.5

TV camera

γ = 0.45

Contemporary color management requirements

Alexa 5D

Vimeo editorial

HD monitor

graphics

DVD

film scan

QT MOV ...

VFX ...

delivery

Color management system

Color management system

Rendering intent defines how values are translated from one color gamut to another: 

Perceptual



Saturation



Relative colorimetric



Absolute colorimetric

Color management system

Calibration and profiling:



Calibration brings device to factory recommended specification



Profiling builds a fingerprint of the specific device's differential from a

standard color space specification

Good news!

Color management in most NLEs is much simpler. Color management can be more sophisticated in picture finishing and color correction systems. Sometimes aided by the operating system  Can be dependent on user selected LUTs or matrices 

Transforming the numbers input values

1D LUT  3D LUT 



3X3 matrix

0 1 2 3 4 5

output values R G B 0.034439 0.034439 0.034439 0.034712 0.034712 0.034712 0.034988 0.034988 0.034988 0.035266 0.035266 0.035266 0.035546 0.035546 0.035546 0.035828 0.035828 0.035828 ...

If input R or G or B = 0 Output R or G or B = 0.034439

Transforming the numbers

1D LUT  3D LUT 



3X3 matrix

Rec. 709 vs. DCI-P3 3D color gamut

Transforming the numbers

1D LUT  3D LUT 



3X3 matrix

Mathematical transformation. Not as precise as 3D LUT but adequate for many applications.

How do popular programs color manage?

Media Composer  Creative Cloud 



FCP X

How do popular programs color manage? tape 709 files 601/709

MC 6.x Rec. 709

TV monitor Rec. 709

sRGB files user choices

How do popular programs color manage? 0

0

255

16

0 mV superblack

235 255

700 mV

superwhite

How do popular programs color manage?

without dithering

with dithering

Recent developments

CDL  Scene referred linear 



ACES

Special Thanks

James Mathers, Digital Cinema Society Matt Feury, Avid Technologies

Further reading

Fraser, Murphy and Bunting (2005). Real World Color Management. Berkeley: Peachpit Press. Graham, S. (2002). The Science of Imaging: An Introduction. Bristol: IOP Publishing. Bloch, C. (2007). The HDRI Handbook. Santa Barbara: Rocky Nook. Kennel, G. (2007). Color and Mastering for Digital Cinema. Burlington: Focal Press. www.poynton.com www.lightillusion.com This presentation is available for download at HDhead.com.