How can i plot a color bar for an RGB image ?

RGB = imread('saturn.png');
I = rgb2gray(RGB);
h = [1 2 1; 0 0 0; -1 -2 -1];
I2 = filter2(h,I);
imshow(I2,'DisplayRange',[]), colorbar

I have found the above codes for grayscale image.

Answer 1

[KSSV]

https://in.mathworks.com/help/images/ref/colorcloud.html

[sam CP]

if true
close all;
clear all;
clc
warning off;
I = imread('demo.jpg');
colorcloud(I,'hsv');
end

Getting the following error "Undefined function or variable 'colorcloud'."

[Walter Roberson]

colorcloud was new as of R2016b.

You did not enter your MATLAB Release information when you created the question, so we are going to assume you have the newest release.

[sam CP]

I'm using 2016a

Answer 2

[Walter Roberson]

RGB images do not have colorbars. colorbar relates a linear (or log) value to the color the value is mapped to, but RGB images express color directly; there is no linear (or log) value being mapped to a color.

We could create a bar chart relating each RGB color to the number of times that color occurs, but your image has over 150000 RGB colors so you would need like 100 displays end to end even if the bars were only one pixel wide.