How to extract pixel intensity of a grayscale image (*.jpg) to a MS Excel table

Hello everyone, I am a very new beginner with image processing and Mathlab. Please help me with the following isse, many thanks in advance !

I have a grayscale image. I'd like to extract its pixel intensities to a MS Excel table with three vectors, including pixel intensiy, X and Y coordinates of the pixel.

Answer 1

[Sameer]

Hi Mac

From my understanding, you want to extract pixel intensities from a grayscale image and save them in an 'MS Excel' table with the corresponding X and Y coordinates.

Here’s how you can achieve it:

1. Read the Image: First, ensure your grayscale image is accessible, either in the current directory or by providing the full path.

% Read the grayscale image

img = imread('your_image.jpg');

2. Extract Pixel Intensities and Coordinates: Loop through each pixel to gather intensity values and their coordinates.

% Get the size of the image
[rows, cols] = size(img);

% Initialize vectors for storing pixel data
pixelIntensity = [];
xCoordinates = [];
yCoordinates = [];
% Loop through each pixel
for x = 1:cols
    for y = 1:rows
        % Append data to vectors
        pixelIntensity = [pixelIntensity; img(y, x)];
        xCoordinates = [xCoordinates; x];
        yCoordinates = [yCoordinates; y];
    end
end

3. Write Data to Excel: Utilize "writetable" function to save the extracted data into an Excel file.

% Create a table from the vectors
dataTable = table(xCoordinates, yCoordinates, pixelIntensity, ...
'VariableNames', {'X', 'Y', 'Intensity'});

% Write the table to an Excel file
writetable(dataTable, 'pixel_data.xlsx');

Please refer to the below MathWorks documentation link:

https://www.mathworks.com/help/matlab/ref/imread.html

https://www.mathworks.com/help/matlab/ref/writetable.html

Hope this helps!

[Image Analyst]

It's best not to use built-in function names, like image, as the names of your variables. Doing so could cause problems if you later want to use that function.

[Sameer]

Edited, Thanks!

[Mac]

It works very well. I really appreciate.

Answer 2

[Image Analyst]

See my attached demo that writes an image out to a CSV text file that can be read in by Excel.

[Mac]

Thanks sir