computer graphics systems color principles

Download Computer Graphics Systems Color principles

Post on 31-Dec-2015

19 views

Category:

Documents

3 download

Embed Size (px)

DESCRIPTION

Donald House Artists slides by Lynette House. Computer Graphics Systems Color principles. Color from Physics Viewpoint. Color from Physiological Viewpoint. 3 cone response curves Luminance efficiency. Color from Artists Viewpoint. Hue Saturation Value. Hue - Paint Mixing. - PowerPoint PPT Presentation

TRANSCRIPT

  • Computer Graphics SystemsColor principles

    Donald HouseArtists slides by Lynette House

  • Color from Physics Viewpoint

  • Color from Physiological Viewpoint 3 cone response curves Luminance efficiency

  • Color from Artists ViewpointHueSaturationValue

  • Hue - Paint MixingPhysical mix of opaque paintsPrimary: RYBSecondary: GOVNeutral: R + Y + B

  • Hue - Ink MixingSubtractive mix of transparent inksPrimary: CMYSecondary: RGB~Black: C + M + YActually use CMYK to get true black

  • Hue - Ink MixingAssumption: ink printed on pure white paper CMY = White RGB:C = 1 R, M = 1 G, Y = 1 B

    CMYK from CMY:K = min(C, M, Y)C = C K, M = M K, Y = Y - K

  • Hue - Light MixingAdditive mix of colored lightsPrimary - RGBSecondary - CMYWhite - R + G + BShow demonstration of optical mixing

  • Saturation Purity of color

  • Value LuminanceDark to LightValue rangeHigh keyMiddle keyLow key

  • RGB Color WheelWarm/CoolComplements Split ComplementAnalogous

  • HSV Color Model HSV is a projection of the RGB spaceRGB cubeHSV top viewHSV cone

  • HSV Color Model Hue, an angular measure (0 - 360)

  • HSV Color Model Saturation, a fractional measure (0 - 1)

  • HSV Color Model Value, a fractional measure (0 - 1)

  • CIE 1931 Study Color Matching Experiment

  • CIE Color Matching Functions CIE RGB Matching Functions CIE XYZ Matching Functions

  • RGB from Spectrum

    RGB = x d

  • XYZ from Spectrum

    XYZ = x d

  • CIE xyY color model is used to catalog colors:

    x = X / (X + Y + Z)y = Y / (X + Y + Z)Y = luminance

    CIE xyY from CIE XYZ

  • CIE xyY Color Cone

  • CIE xyY Typical Display Gamut

  • CIE Lu*v* and Lab Perceptually Uniform Spaces Lu*v* rescales xyY Lab color opponents

  • Color Picker

  • End

    *************************