VDU colorimetry zDigital input - luminance output ygamma-correction ychannel interdependence ylocal interdependence zColour correction matrix zHard-copy / soft-copy transformation ycolour management ycognitive effects

Video Display Unit (VDU) zWhite point setting differences CCT x y xD xD xD

VDU monitor zInput: bit streams zDisplay processor: converting for output device zObject oriented storage of characters: scaling, rotation, etc. zBuffer memory

Buffer memory  Size: Number of pixels x Bits in pixel  3 bit colour 640 x 400 x 3 bit colour: 95 kbyte (3 bit colour: R, G, B: on - off)  8 bit per colour channel: 640 x 400 = pixels x 8 x 3 = 768 kbyte  Refresh rate: 640 x 400 x 3 = bits, 70 frames/sec: 54 Mbit/s

3 bit colour palette

Display processing zCharacter generation -ASCII 7 bit code: 128 characters -ISO 8 bit code: 256 characters -Code sheets -Additional information -Font & colour -Character outline

Display processing zGraphics generation -Graphical user interface -Windows -Icons (symbols) -Mouse & pointer

Colour systems  Basic 8-colour set R, G, B on - off: 3 bits per character  Logically defined colours: CLUTs  Dithering -spatial dithering; temporal dithering

Spatial dithering  2 x 2 groups: 5 luminance levels z2 x 2 arrays, 2 bits per pixel: y2 8 =256 arrangements: y35 colours, 23 chromaticities

Colour look-up tables zLogical and actual colour yCLUT: image as bit-codes per pixel in terms of a set of logical colours.

Digital-to-Analogue Conversion zn bit code for primary colour: 2 n levels: yin CLUT  -correction possible zRGB  HVC conversion y8 bit palettes

Anti-aliasing zAnti-aliasing processors: Real time interpolation in CLUT

System structure