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rgb2ntsc

Convert RGB color values to NTSC color space

Syntax

yiqmap = rgb2ntsc(rgbmap)
YIQ = rgb2ntsc(RGB)

Description

yiqmap = rgb2ntsc(rgbmap) converts the m-by-3 RGB values in rgbmap to NTSC color space. yiqmap is an m-by-3 matrix that contains the NTSC luminance (Y) and chrominance (I and Q) color components as columns that are equivalent to the colors in the RGB colormap.

YIQ = rgb2ntsc(RGB) converts the truecolor image RGB to the equivalent NTSC image YIQ.

Class Support

RGB can be of class uint8, uint16, int16, single, or double. RGBMAP can be double. The output is double.

Examples

collapse all

This example shows how to convert an image from RGB to NTSC color space.

Read an RGB image into the workspace.

RGB = imread('board.tif');

Convert the image to YIQ color space.

YIQ = rgb2ntsc(RGB);

Display the NTSC luminance value, represented by the first color channel in the YIQ image.

imshow(YIQ(:,:,1));
title('Luminance in YIQ Color Space');

Tips

In the NTSC color space, the luminance is the grayscale signal used to display pictures on monochrome (black and white) televisions. The other components carry the hue and saturation information.

rgb2ntsc defines the NTSC components using

[YIQ]=[0.2990.5870.1140.5960.2740.3220.2110.5230.312][RGB]

Introduced before R2006a

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