1. Computational and Biological Vision “Colors Out Of Space” Digital color representation, color spaces and more! Amir Eluk Software Engineering

2. Introduction 0 Representation 0 Color Model 0 Color Space 0 Gamut 0 Color Blending Modes

3. sRGB 0 Additive Color Mixing 0 Easy to generate physically 0 Standard for most devices 0 Poor gamut 0 Unintuitive 0 Biologically? (cones response)

5. Color Gamut sRGB Adobe RGB Adobe Wide Gamut ProPhoto RGB

6. CMYK 0 Subtractive Color Mixing 0 What is K for? 0 Used by printed media

7. HSV/HSL 0 More intuitive 0 Easier to pick colors 0 Not perceptually uniform

8. L.a.b 0 Easy to pick colors 0 Can be perceptually uniform 0 Replicate opposite color theory

9. L.a.b L a B (Dichromat types?)

11. Perceived Brightness level

13. Histogram Comparison RGB Lightness (Lab) Close but not equal, why?

14. Histogram Comparison Green (RGB)Lightness (Lab) A coincidence ?

15. Image Bank & (table of mean absolute difference)......

16. similarity Lightness & Green: 2.1 Lightness & RGB: 2.5 Lightness & RGB: 27.5 Lightness & Green == Lightness and RGB: 8.4 Lightness and Blue: 24.6

17. Conclusions 0 The brightness of an RGB image is composed of its three channels with most weight given to the Green channel, Red comes second followed by blue. 0 This uneven contribution to the brightness is the reason why simple average of RGB values is not the exact brightness of the image.

18. Questions ?