Have a look at https://www.mathworks.com/matlabcentral/mlc-downloads/downloads/submissions/9554/versions/5/previews/numerical-tour/multidim_color/index.html

https://au.mathworks.com/help/images/ref/impixel.html

Have you looked into mathworks.com?

clc; % Clear command window.

clear; % Delete all variables.

close all; % Close all figure windows except those created by imtool.

imtool close all; % Close all figure windows created by imtool.

workspace; % Make sure the workspace panel is showing.

fontSize = 15;

% Read in a standard MATLAB color demo image.

folder = fullfile(matlabroot, '\toolbox\images\imdemos');

baseFileName = 'peppers.png';

fullFileName = fullfile(folder, baseFileName);

% Get the full filename, with path prepended.

fullFileName = fullfile(folder, baseFileName);

if ~exist(fullFileName, 'file')

% Didn't find it there. Check the search path for it.

fullFileName = baseFileName; % No path this time.

if ~exist(fullFileName, 'file')

% Still didn't find it. Alert user.

errorMessage = sprintf('Error: %s does not exist.', fullFileName);

uiwait(warndlg(errorMessage));

return;

end

end

rgbImage = imread(fullFileName);

% Get the dimensions of the image. numberOfColorBands should be = 3.

[rows columns numberOfColorBands] = size(rgbImage);

% Display the original color image.

subplot(3, 4, 1);

imshow(rgbImage);

title('Original color Image', 'FontSize', fontSize);

% Enlarge figure to full screen.

set(gcf, 'Position', get(0,'Screensize'));

% Extract the individual red, green, and blue color channels.

redChannel = rgbImage(:, :, 1);

greenChannel = rgbImage(:, :, 2);

blueChannel = rgbImage(:, :, 3);

% Display the individual red, green, and blue color channels.

subplot(3, 4, 2);

imshow(redChannel);

title('Red Channel', 'FontSize', fontSize);

subplot(3, 4, 3);

imshow(greenChannel);

title('Green Channel', 'FontSize', fontSize);

subplot(3, 4, 4);

imshow(blueChannel);

title('Blue Channel', 'FontSize', fontSize);

% Generate a noisy image. This has salt and pepper noise independently on

% each color channel so the noise may be colored.

noisyRGB = imnoise(rgbImage,'salt & pepper', 0.05);

subplot(3, 4, 5);

imshow(noisyRGB);

title('Image with Salt and Pepper Noise', 'FontSize', fontSize);

% Extract the individual red, green, and blue color channels.

redChannel = noisyRGB(:, :, 1);

greenChannel = noisyRGB(:, :, 2);

blueChannel = noisyRGB(:, :, 3);

% Display the noisy channel images.

subplot(3, 4, 6);

imshow(redChannel);

title('Noisy Red Channel', 'FontSize', fontSize);

subplot(3, 4, 7);

imshow(greenChannel);

title('Noisy Green Channel', 'FontSize', fontSize);

subplot(3, 4, 8);

imshow(blueChannel);

title('Noisy Blue Channel', 'FontSize', fontSize);

% Median Filter the channels:

redMF = medfilt2(redChannel, [3 3]);

greenMF = medfilt2(greenChannel, [3 3]);

blueMF = medfilt2(blueChannel, [3 3]);

% Find the noise in the red.

noiseImage = (redChannel == 0 | redChannel == 255);

% Get rid of the noise in the red by replacing with median.

noiseFreeRed = redChannel;

noiseFreeRed(noiseImage) = redMF(noiseImage);

% Find the noise in the green.

noiseImage = (greenChannel == 0 | greenChannel == 255);

% Get rid of the noise in the green by replacing with median.

noiseFreeGreen = greenChannel;

noiseFreeGreen(noiseImage) = greenMF(noiseImage);

% Find the noise in the blue.

noiseImage = (blueChannel == 0 | blueChannel == 255);

% Get rid of the noise in the blue by replacing with median.

noiseFreeBlue = blueChannel;

noiseFreeBlue(noiseImage) = blueMF(noiseImage);

% Reconstruct the noise free RGB image

rgbFixed = cat(3, noiseFreeRed, noiseFreeGreen, noiseFreeBlue);

subplot(3, 4, 9);

imshow(rgbFixed);

title('Restored Image', 'FontSize', fontSize);

You may be interested in

Preprint A New Model of Color Vision for Remote Sensing (A Condensed Version) 1