hyperspectral imaging signature plot

I have hyperspectral imaging raw data.

How can I get like this plot (reflectance, wavelength)

[Rik]

This looks like a normal plot to me. What have you tried?

[Alexai]

I have raw data(including hdr file)

But I want to know related code.

[Rik]

You didn't answer my question. Have a read here and here. It will greatly improve your chances of getting an answer.

You can also have a look at the answer Sulaymon posted.

Answer 1

[Sulaymon Eshkabilov]

It can be obtained with the following steps:

(1) Import your HSI data into MATLAB. In other words, read your hypespectral images. You may use any available apps or HSI data reader apps, or 3rd party developed toolboxes, like this one: https://www.mathworks.com/matlabcentral/fileexchange/61630-matlab-hyperspectral-toolbox

(2) Just plot using plot() command, for instance.

(3) If your HSI data are noisy, you can smooth them by using smooth() or smoothdata(), sgolayfilt().

Answer 2

[Image Analyst]

Read your images into a 3-D array, then do this:

image3d = rand(100, 100, 32); % Create sample data.
[rows, columns, numChannels] = size(image3d)
figure;
hold on;
for row = 1 : rows
    fprintf('Plotting spectra from row #%d of %d.\n', row, rows)
    for col= 1 : columns
        thisSpectra = squeeze(image3d(row, col, :));
        plot(thisSpectra, '-');
    end
    % Update plot
    if mod(row, 20) == 0 || row == 1
        caption = sprintf('Spectra 1 though %d.\n', row * columns);
        title(caption);
        xlabel('Wavelength (nm)');
        ylabel('Reflectance');
        drawnow;
    end
end
grid on;
xlabel('Wavelength');
ylabel('Reflectance (nm)');
fprintf('Done plotting %d spectra.\n', rows * columns)

Answer 3

[Mandar]

Install the hyperspectral imaging library from this link. Use “hypercube” function to read the hyperspectral data. The function returns the hypercube object. The “DataCube” property of the object holds the hyperspectral data in 3-D numeric array. Access the data and use “plot” function to get the reflectance values on Y-axis for respective wavelengths on X-axis.