Color Space

- Textbook
- Interaction of color
**Color Science**: Concepts and Methods, Quantitative Data and Formulae- Colorimetry: Understanding the CIE System
- Billmeyer and Saltzman's Principles of Color Technology
- Measuring Colour by Hunt
- Contrast Sensitivity of the Human Eye and Its Effects On Image Quality

- Introduction

- Lightness

- Intensity is radiant power in a particular direction.
- Radiance is intensity per unit projected area.

- Color Theory

- Color Addition

*Grassmann's Law**Color Depth**CIE 1931 Color Space**XYZ Color Space**RGB to/from XYZ conversion**RGB Color Space**sRGB(standard RGB)/HDTV RGB**LMS**CIE 1976 (L*,a*,b*)**LIE 1976 (L*,u*,v*)**Delta-E*

$R = R_1+R_2$

$G = G_1+G_2$

$B = B_1+B_2$

**Chromaticity diagrams**- The Chromaticity diagram is a two-variable system for specifying the hue and saturation of colors (together called chroma) producible using a particular set of primaries.
- Gamut mapping

- xyY color space
- The xyY color space is a transformation of the CIE XYZ color space onto 2 dimensions.
- This allows the illustration of color using a graph like the Chromaticity Diagram and it removes the luiminance component of color.
- The CIE 1924 photopic luminosity function is included in the CIE 1931 color-matching functions as the y function.

- Luminosity function

- The formulas for determining xyY are as follows:
- x = X/(X+Y+Z)
- y = Y/(X+Y+Z)
- Y = Y

- Recalculate X and Z
- z = Z/(X+Y+Z) = (1-x-y)
- X = (Y/y)*x
- Z = (Y/y)*z = (Y/y)*(1-x-y)

- Luma+2 color difference signals

- YUV
**YUV**and**Y'UV**were used for a specific**analog**encoding of color information in television systems, while**YCbCr**was used for**digital**encoding of color information suited for video and still-image compression and transmission such as MPEG and JPEG.

- approximate the way humans perceive and interpret color

*Munsell Color System**HSI(Hue, Saturation, Intensity)/HSL(Hue, Saturation, Lightness)**HSB(Hue, Saturation, Brightness)/HSV(Hue, Saturation, Value)*

- Munsell Color Cascade

- Subtractive
- CMYK

page revision: 153, last edited: 03 May 2016 03:48