`rgb2hsv`

Converts colors from red-green-blue to hue-saturation-value.

Category: Graphics > Formatting and Annotation

Syntax

hsv = rgb2hsv(rgb)

Converts an m-by-3 colormap or an image of size m-by-n-by-3 from RGB to HSV.

Description

The value is the largest of the three channels and the saturation is the spread between largest and smallest, relative to the value. The hue is the position on the color wheel as a fraction: 0 for red, 1/3 for green and 2/3 for blue. For a gray color, where all channels are equal, saturation and hue are 0.

The conversion is useful to change brightness or saturation of a picture without shifting its colors. The inverse is hsv2rgb.

Input arguments

rgb: Colormap or image with values between 0 and 1 in the last dimension. Integer images are converted to double first.

Output arguments

hsv: Array of the same size with hue, saturation and value in the range 0 to 1.

Example

Red, cyan and a gray

rgb2hsv([1 0 0; 0 1 1; 0.5 0.5 0.5])

Output

ans = 3×3

         0    1.0000    1.0000
    0.5000    1.0000    1.0000
         0         0    0.5000

rgb2hsv