HSV Color space: True color pictures with 3 components (RGB)each has 256 possible value, so we have up to16,777,216 possible colors: Controlling this huge amount of possibilities isalmost impossible without the HsV spaceHSV provides an intuitivemethod for color selectionApplications: imageprocessing, fractalpictures, ray tracing
HSV Color space • True color pictures with 3 components (RGB), each has 256 possible value, so we have up to 16,777,216 possible colors. • Controlling this huge amount of possibilities is almost impossible without the HSV space. HSV provides an intuitive method for color selection. • Applications: image processing, fractal pictures, ray tracing
HSV: HsV: a color space in cone-shaped- Hue (色调) means the base color, which is a mainfactor indicates difference between colors Saturation(饱和度)is for purity of color (decreaseHue= adding white)_Value of brightness(亮度)Luminance of lights,SaturatiorValue(decrease = adding blackmore user-friendly than RGB
HSV • HSV: a color space in cone-shaped – Hue (色调) means the base color, which is a main factor indicates difference between colors. – Saturation(饱和度) is for purity of color (decrease = adding white) – Value of brightness(亮度) Luminance of lights, (decrease = adding black more user-friendly than RGB
CIE XYZ: CIE XYZ color space- Proposed by CIE (International Commission onIllumination) in 1931: It can represent all perceptible colors (whileRGB not)- most used in color science- based on human perception studies
CIE XYZ • CIE XYZ color space – Proposed by CIE (International Commission on Illumination ) in 1931 • It can represent all perceptible colors (while RGB not) – most used in color science – based on human perception studies
CIE XYZ (Chromaticity Diagram)This diagram shows how to use XYZ torepresent colors. Z is equal to 1 - x - y.0.9520CLEITiCTYspectrallocusDIAGRAM0.85405100.7Green5600.65005800.5YellowCyan0.4600A0.3490Red700Blue0.2480Purplepurpleli0.1400+X0.10.20.30.40.50.60.70.8
CIE XYZ (Chromaticity Diagram) This diagram shows how to use XYZ to represent colors. Z is equal to 1 – x – y
Image & Pixel: Image- image could be treated as a 2-dimensionaldiscrete function f(x,y)-eachdiscretegrid iscalledpixel（象素）- Usually, each pixel has a RGB( or RGBA)value for color image ora scalar value for gray image
Image & Pixel • Image – image could be treated as a 2-dimensional discrete function f(x,y) – each discrete grid is called pixel (象素) – Usually, each pixel has a RGB( or RGBA) value for color image or a scalar value for gray image