hsv2rgb

Convert HSV colors to RGB

Syntax

RGB = hsv2rgb(HSV)

rgbmap = hsv2rgb(hsvmap)

Description

RGB = hsv2rgb(HSV) converts the hue, saturation, and value (HSV) values of an HSV image to red, green, and blue values of an RGB image.

rgbmap = hsv2rgb(hsvmap) converts an HSV colormap to an RGB colormap.

Examples

Convert HSV Matrix to a Colormap

Create a three-column HSV matrix that specifies five shades of blue. In this case, hue and value are constant, while saturation varies between 1.0 and 0.0.

hsv = [.6 1 1; .6 .7 1; .6 .5 1; .6 .3 1; .6 0 1]; 

Convert the HSV matrix to a colormap by calling hsv2rgb. Then use that colormap in a surface plot.

rgb = hsv2rgb(hsv);
surf(peaks);
colormap(rgb);
colorbar

Convert 3-D HSV Array to a Truecolor Image

Create a 2-by2-by-3 HSV array that specifies four shades of blue.

hsv(:,:,1) = ones(2,2)*.6;
hsv(:,:,2) = [1 .7; .3 0];
hsv(:,:,3) = ones(2,2);

Convert the HSV array to a truecolor image using hsv2rgb. Then display the image.

rgb = hsv2rgb(hsv);
image(rgb);

Input Arguments

HSV — HSV image

m-by-n-by-3 numeric array

HSV image, specified as an m-by-n-by-3 numeric array with values in the range [0, 1]. The third dimension of HSV defines the hue, saturation, and value for each pixel, respectively, as described in the table.

Attribute	Description
Hue	Value from 0 to 1 that corresponds to the color’s position on a color wheel. As hue increases from 0 to 1, the color transitions from red to orange, yellow, green, cyan, blue, magenta, and finally back to red.
Saturation	Amount of hue or departure from neutral. 0 indicates a neutral shade, whereas 1 indicates maximum saturation.
Value	Maximum value among the red, green, and blue components of a specific color.

Data Types: double | single | logical

hsvmap — HSV colormap

c-by-3 numeric matrix

HSV colormap, specified as a c-by-3 numeric matrix with values in the range [0, 1]. Each row of hsvmap is a three-element HSV triplet that specifies the hue, saturation, and value components of a single color of the colormap.

Data Types: double

Output Arguments

RGB — RGB image

m-by-n-by-3 numeric array

RGB image, returned as an m-by-n-by-3 numeric array with values in the range [0, 1]. The third dimension of RGB defines the red, green, and blue intensity of each pixel, respectively. The image has the same data type as the HSV image, HSV.

Data Types: double | single

rgbmap — RGB colormap

c-by-3 numeric matrix

RGB colormap, returned as a c-by-3 numeric matrix with values in the range [0, 1]. Each row of rgbmap is a three-element RGB triplet that specifies the ref, green, and blue components of a single color of the colormap. The colormap has the same data type as the HSV colormap, hsvmap.

Data Types: double | single

References

[1] Smith, A. R. “Color Gamut Transform Pairs”. SIGGRAPH 78 Conference Proceedings. 1978, pp. 12–19.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using MATLAB® Coder™.

GPU Code Generation
Generate CUDA® code for NVIDIA® GPUs using GPU Coder™.

Thread-Based Environment

Run code in the background using MATLAB® backgroundPool or accelerate code with Parallel Computing Toolbox™ ThreadPool.

This function fully supports thread-based environments. For more information, see Run MATLAB Functions in Thread-Based Environment.

GPU Arrays

Accelerate code by running on a graphics processing unit (GPU) using Parallel Computing Toolbox™.

The hsv2rgb function fully supports GPU arrays. To run the function on a GPU, specify the input data as a gpuArray (Parallel Computing Toolbox). For more information, see Run MATLAB Functions on a GPU (Parallel Computing Toolbox).

Distributed Arrays

Partition large arrays across the combined memory of your cluster using Parallel Computing Toolbox™.

This function fully supports distributed arrays. For more information, see Run MATLAB Functions with Distributed Arrays (Parallel Computing Toolbox).

Version History

Introduced before R2006a