Color Images CS/BIOEN 4640: Image Processing Basics April 5, 2012 - - PowerPoint PPT Presentation

color images
SMART_READER_LITE
LIVE PREVIEW

Color Images CS/BIOEN 4640: Image Processing Basics April 5, 2012 - - PowerPoint PPT Presentation

Color Images CS/BIOEN 4640: Image Processing Basics April 5, 2012 RGB Color Space Source: Wikipedia Additive vs Subtractive Color Models Additive Color Model Subtractive Color Model Visible Light Spectrum Monochromatic colors are light


slide-1
SLIDE 1

Color Images

CS/BIOEN 4640: Image Processing Basics April 5, 2012

slide-2
SLIDE 2

RGB Color Space

Source: Wikipedia

slide-3
SLIDE 3

Additive vs Subtractive Color Models

Additive Color Model Subtractive Color Model

slide-4
SLIDE 4

Visible Light Spectrum

◮ Monochromatic colors are

light at a single wavelength

◮ Some colors (cyan, pink, ...)

cannot be represented by a single wavelength

◮ These colors are a mixture or

spectrum of wavelengths

Source: Wikipedia

slide-5
SLIDE 5

CIE XYZ Color Space

slide-6
SLIDE 6

CIE XYZ Color Space

460 480 500 520 540 560 580 600 620 x 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 y 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9

slide-7
SLIDE 7

MacAdam Ellipses

Source: Wikipedia

slide-8
SLIDE 8

Gamut

Maximum range of colors a display device (monitor, projector, etc.) can reproduce.

Source: Wikipedia

slide-9
SLIDE 9

Hue/Saturation/Value (HSV)

Source: Wikipedia

slide-10
SLIDE 10

Hue/Luminance/Saturation (HLS)

Source: Wikipedia

slide-11
SLIDE 11

Converting RGB to Grayscale

Simple average:

Y = R + G + B 3

Better weights for perception:

Y = 0.299 R + 0.587 G + 0.114 B

slide-12
SLIDE 12

Exploring Colorspaces in ImageJ

Check this out: http://imagej.nih.gov/ij/plugins/ color-inspector.html