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Introduction to Color Managementfor Film and TVIgor Riđanović
Why color manage in food industry?
Why color manage in retail?
commonsource
multipledisplaydevices
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
Rods see low light and no color
Three type of cones can see color Near logarithmic response to luminance
Hans-Werner Hunziker
How do we see light and color?
S, M and L cones
How do we see light and color?
linear light intensity
How do we see light and color?perceivedbrightness
perceivedbrightness
doubling light intensity
Wolphram|Alpha
Additive and subtractive color mixing
Pko Cantus
Color model—an abstract primary color mixing principle
Color space—specific values for the primaries Color gamut—unambiguous color set defined by the primaries
Color model and color space
CIE XYZ(1931) color space
CIE xychromaticity diagram
PAR
sRGB color space
Device independent (example: CIE XYZ)
Device dependent (example: Rec. 709)
Color space classification
Examples:
Traditional CMYK press Analog and Digital TV
Device dependent color
In RGB color model each pixel is represented bythe additive mix of its three channels (R + B + G)
R 205G 012B 005
R 000G 000B 000
R 255G 255B 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
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
Values are intrinsically tied to the device
R 255G 255B 000
sRGB color space(computer monitor)
R 255G 255B 000
mystery color space(some handheld device)
Device dependent color—numerical representation
R 205G 012B 005
R 205G 012B 005
R 205G 012B 005
device 1
device 2
source device
Device dependent color
R ?G ?B ?
R 205G 012B 005
device 2
source device
Device dependent color
R 212G 008B 010
R 205G 012B 005
device 2
source device
Device dependent color
CMS
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
Rec. 709 vs.DCI-P33D color gamut
Device dependent color—gamut
Device dependent color—gamma
linear gamma 2.2 gammaWolfram|Alpha
Device dependent color—dynamic range
higher dynamic range
lower dynamic range
reduced dynamic rangegamma mismatch
original gamut mismatch
Case Study: Black and White TV (simplified)
subjectcamera
TV set
OTA broadcast
video
Traditional TV color management
Single input, single output
TV camera editorial TV monitor
TV camera
γ = 0.45
γ = 2.5
Contemporary color management requirements
5D editorial HD monitor
film scan
Alexa
graphics
Vimeo
DVD
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
1D LUT
3D LUT 3X3 matrix
R G B0.034439 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 = 0Output R or G or B = 0.034439
012345
output valuesinput values
Transforming the numbers
1D LUT
3D LUT 3X3 matrix
Rec. 709 vs.DCI-P33D 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?
601/709 MC 6.x TV monitor
sRGB
tape 709
files
files
user choices
Rec. 709 Rec. 709
How do popular programs color manage?
0 255
0 25523516
0 mV
16
700 mV
superblack 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.comwww.lightillusion.com
This presentation is available for download at HDhead.com.
