299 0587 0114r i 0596 0275 0321g q 0212 0532

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Unformatted text preview: s, but still not able to span the entire color space – Some color printers use more than just CMYK NTSC YIQ Model • The National Television Standards Committee (NTSC) standard uses a color model called YIQ: – Y luminance – I and Q chromaticity ÈY ˘ È0.299 0.587 0.114˘ÈR ˘ Í˙ Í ˙Í ˙ ÍI ˙ = Í0.596 -0.275 -0.321˙ÍG˙ Í˙ Í ˙Í ˙ ÎQ˚ Î0.212 -0532 0.311˚ÎB ˚ • Television Signals – Color TV broadcasts are YIQ †– “Black-and-white” (grey) TV uses Y only Device Primaries and Gamuts • Different devices have different primaries and different gamuts – Scanners – Monitors – Printers • Two major problems working with color: – Calibration: “talking the same color language” – Out-of-gamut limitations HSI Color Model • One axis is intensity (luminance) • The plane perpendicular to this axis represents chromaticity – Angle = hue – Distance from center = saturation • Can map this plane using a triangle, hexagon, or circle HSI Color Model HSI Color Model HSI Color Model Other Color Models • Hue-Saturation-Value (HSV) – Like HSI but with only one cone • • • • Hue-Lightness-Saturation (HLS) Hue-Value-Chroma (HVC) CIE LUV CIE La*b* – Attempts to be perceptually linear Pseudocolor (Indexed Color) • For some applications, you may want to store fewer than 24 bits per pixel – Older/less-expensive video buffers – Compression (used in GIF compression) • Use a lookup table to map values in the image buff...
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This document was uploaded on 03/15/2012.

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