## How do you convert RGB to LAB color space?

lab = rgb2lab( RGB ) converts sRGB values to CIE 1976 L*a*b* values. lab = rgb2lab( RGB , Name,Value ) specifies additional conversion options, such as the color space of the RGB image, using one or more name-value pair arguments.

How do I add RGB color in MATLAB?

If you want to create RGB image from some kind of matrix, try this:

1. image=zeros(300,400,3); %initialize.
2. image(:,1:100,1)=0.5; %Red (dark red)
3. image(:,101:200,1)=1; %Red (maximum value)
4. image(1:100,:,2)=rand(100,400); %Green.
5. figure, imshow(image)

### What is Lab vs RGB?

RGB operates on three channels: red, green and blue. Lab is a conversion of the same information to a lightness component L*, and two color components – a* and b*. Lightness is kept separate from color, so that you can adjust one without affecting the other.

What is the a axis in CIE L * a * b?

a* and b* are color directions: +a* is the red axis, -a’ is the green axis, +b* is the yellow axis and -b* is the blue axis. Plotting the a* and b* on the color space shows the chromaticity of the apple and the L* expresses the lightness of the color.

## How do you set a color plot in MATLAB?

Create a line plot and use the LineSpec option to specify a dashed green line with square markers. Use Name,Value pairs to specify the line width, marker size, and marker colors. Set the marker edge color to blue and set the marker face color using an RGB color value.

What is Matlab Lab color?

Lab color space is a 3-axis color system with dimension L for lightness and a and b for the color dimensions. Working with the Lab color space includes all of colors in the spectrum, as well as colors outside of human perception.

### What is LAB color space used for?

The Lab* color space allows you to quantify the color utilizing an independent color space. This means that the values give you an independent value representing that color. In the simplest terms, if you have the same Lab* values you will have the same color, different lab* values a different color.

What is L*a*b image?

The L*a*b* color space is derived from the CIE XYZ tristimulus values. The L*a*b* space consists of a luminosity ‘L*’ or brightness layer, chromaticity layer ‘a*’ indicating where color falls along the red-green axis, and chromaticity layer ‘b*’ indicating where the color falls along the blue-yellow axis.

## How does L*a*b * work?

Chromatic (‘real’) colors are described by using the two axes in the horizontal plane. The a*-axis is the green-red axis and the b*-axis goes from blue (-b*) to yellow (+b*). Each color is represented by a color point (L*, a*, b*) in the color space; L*, a* and b* are the color coordinates of the color point.