tailieunhanh - CS 450: Color

CS 450: Color presents about Color Receptors; The Luminous-Efficiency Function; The RGB Color Model; Luminance and Chromaticity; Luminance; Luminance; The CIE Chromaticity Diagram; Color Gamuts; The RGB Model; The CMYK Model; Tints and Shades. | CS 450 Color 1 Color Receptors Visible light is in the range 400 nm blue to 700 nm red . Cones have three different kinds of color-sensitive pigments each responding to a different range of wavelengths. These are roughly red green and blue in their peak response but each responds to a wide range of wavelengths. The combination of the responses of these different receptors gives us our color perception. This is called the tristimulus model of color vision. CS 450 Color 2 The Luminous-Efficiency Function Because the three receptors respond with different amplitudes and different peak frequencies the apparent brightness of a color depends not only on the luminance but on the wavelength. Plotting perceived luminance as a function of wavelength gives the luminous-efficiency function of the eye. CS 450 Color 3 The RGB Color Model The simplest color model is to attempt to model these three stimulus values red green and blue. 24-bit color one byte for red one byte for green one byte for blue Each is called a channel. Problem Machine word sizes are usually 32 bit not 24 bit. Solution Use 32 bits per pixel 24 color 3 channels 8 alpha .