Extract numeric values ​​from a colormap

Hello everyone

I am trying to extract the numerical values ​​of a variable represented in the following colormap with its respective colorbar (which I also attach in PDF format):

It would be very desirable to be able to create a database based on the spatial deviation from the center of the hexagon along the directions defined by the a1 and a2 vectors as a fraction of a0, being a0 the modulus of the aforementioned vectos:

Any idea?

Answer 1

[Image Analyst]

You need to read that colorbar part of the image and then divide by 255.

colorsInBar = rgbImage(row1:row2, col1:col2, :);
[r, g, b] = imsplit(colorsInBar);
cMap = double([r(:), g(:), b(:)]) / 255;

You may be interested to see how I did it for thermal images:

https://www.mathworks.com/matlabcentral/fileexchange/113995-thermal-image-color-to-temperature?s_tid=srchtitle

To get the numbers you can use ocr in the Computer Vision Toolbox, but the numbers must be at least 20 pixels high.