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How can I analyze my uploaded heatmap pictures ?

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Elif
Elif on 28 Jul 2021
Commented: Elif on 6 Aug 2021
I need to upload the heated map pictures (which I exported from another program) with color bar and then I should compare them to see which one has the greatest magnitude. The code must shows the hottest spots for each pictures ,also it needs to tell which picture have the greatest magnitude. Can anyone help me with this code? Is there any releated code which can helps me ?

Accepted Answer

Image Analyst
Image Analyst on 6 Aug 2021
Well you did something wrong when you tried to adapt my demo. Try it this way:
% Take a thermal RGB image from the FLIR One camera and uses the embedded color bar to determine temperatures from the colors and make a temperature image.
clc; % Clear the command window.
close all; % Close all figures (except those of imtool.)
clear; % Erase all existing variables. Or clearvars if you want.
workspace; % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 15;
%===============================================================================
% Get the name of the image the user wants to use.
baseFileName = '1st_picture.png'; % Base file name with no folder prepended (yet).
% Get the full filename, with path prepended.
folder = pwd; % Change to whatever folder the image lives in.
fullFileName = fullfile(folder, baseFileName); % Append base filename to folder to get the full file name.
if ~isfile(fullFileName)
errorMessage = sprintf('Error: file not found:\n%s', fullFileName)
uiwait(errordlg(errorMessage));
return;
end
fprintf('Transforming image "%s" to a thermal image.\n', fullFileName);
%===============================================================================
% Read in a demo image.
rgbImage = imread(fullFileName);
% Display the image.
subplot(2, 3, 1);
h1 = imshow(rgbImage, []);
axis on;
caption = sprintf('Original Pseudocolor Image, %s', baseFileName);
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Column', 'FontSize', fontSize, 'Interpreter', 'None');
ylabel('Row', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
% grayImage = min(rgbImage, [], 3); % Useful for finding image and color map regions of image.
%=========================================================================================================
% Need to read in the color bar separately.
% Get the full filename, with path prepended.
baseFileName = '1st_picture_colorbar.png'; % Base file name with no folder prepended (yet).
folder = pwd; % Change to whatever folder the image lives in.
fullFileName = fullfile(folder, baseFileName); % Append base filename to folder to get the full file name.
if ~isfile(fullFileName)
errorMessage = sprintf('Error: file not found:\n%s', fullFileName)
uiwait(errordlg(errorMessage));
return;
end
colorBarImage = imread(fullFileName);
% b = colorBarImage(:,:,3);
%=========================================================================================================
% Display the colorbar image.
subplot(2, 3, 2);
h2 = imshow(colorBarImage, []);
axis on;
caption = sprintf('Cropped Colorbar Image');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Column', 'FontSize', fontSize, 'Interpreter', 'None');
ylabel('Row', 'FontSize', fontSize, 'Interpreter', 'None');
hp = impixelinfo();
drawnow;
% Set up figure properties:
% Enlarge figure to full screen.
g = gcf;
g.WindowState = 'maximized';
% Get rid of tool bar and pulldown menus that are along top of figure.
% set(gcf, 'Toolbar', 'none', 'Menu', 'none');
% Give a name to the title bar.
set(gcf, 'Name', 'Demo by ImageAnalyst', 'NumberTitle', 'Off')
%=========================================================================================================
% Get the color map from the color bar image.
storedColorMap = colorBarImage(5:445, 19,:);
% Need to call squeeze to get it from a 3D matrix to a 2-D matrix.
% Also need to divide by 255 since colormap values must be between 0 and 1.
storedColorMap = double(squeeze(storedColorMap)) / 255;
% Need to flip up/down because the low rows are the high temperatures, not the low temperatures.
storedColorMap = flipud(storedColorMap);
subplot(2, 3, 3);
plot(storedColorMap(:, 1), 'r-', 'LineWidth', 3);
hold on;
grid on;
plot(storedColorMap(:, 2), 'g-', 'LineWidth', 3);
plot(storedColorMap(:, 3), 'b-', 'LineWidth', 3);
title('Stored Color Map', 'FontSize', fontSize);
% Convert the subject/sample from a pseudocolored RGB image to a grayscale, indexed image.
indexedImage = rgb2ind(rgbImage, storedColorMap);
% Display the indexed image.
subplot(2, 3, 4);
h4 = imshow(indexedImage, []);
axis on;
caption = sprintf('Indexed Image (Gray Scale Thermal Image)');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Column', 'FontSize', fontSize, 'Interpreter', 'None');
ylabel('Row', 'FontSize', fontSize, 'Interpreter', 'None');
hp = impixelinfo();
drawnow;
%=========================================================================================================
% Now we need to define the temperatures at the end of the colored temperature scale.
% You can read these off of the image, since we can't figure them out without doing OCR on the image.
% Define the temperature at the top end of the scale.
% This will probably be the high temperature.
highTemp = 600;
% Define the temperature at the dark end of the scale
% This will probably be the low temperature.
lowTemp = 0;
% Scale the indexed gray scale image so that it's actual temperatures in degrees C instead of in gray scale indexes.
thermalImage = lowTemp + (highTemp - lowTemp) * mat2gray(indexedImage);
% Display the thermal image.
subplot(2, 3, 5);
h5 = imshow(thermalImage, []);
axis on;
colorbar;
hp = impixelinfo(gcf, [h1, h2, h4, h5]);
title('Floating Point Thermal (Temperature) Image', 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Column', 'FontSize', fontSize, 'Interpreter', 'None');
ylabel('Row', 'FontSize', fontSize, 'Interpreter', 'None');
% Let user mouse around and see temperatures on the GUI under the temperature image.
hp = impixelinfo();
hp.Units = 'normalized';
hp.Position = [0.45, 0.03, 0.25, 0.05];
%=========================================================================================================
% Get and display the histogram of the thermal image.
subplot(2, 3, 6);
histogram(thermalImage, 'Normalization', 'probability');
axis on;
grid on;
caption = sprintf('Histogram of Thermal Image');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Temperature [Degrees]', 'FontSize', fontSize, 'Interpreter', 'None');
ylabel('Frequency [Pixel Count]', 'FontSize', fontSize, 'Interpreter', 'None');
% Get the maximum temperature.
maxTemperature = max(thermalImage(:));
fprintf('The maximum temperature in the image is %.2f\n', maxTemperature);
fprintf('Done! Thanks Image Analyst!\n');
  1 Comment
Elif
Elif on 6 Aug 2021
Thank you so much for your help. It helped me a lot.

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More Answers (1)

Image Analyst
Image Analyst on 2 Aug 2021
Edited: Image Analyst on 2 Aug 2021
It should be easy for you to adapt my attached demo. Since you already have separated the image and the colorbar, you can just begin my demo there, since you don't need to separate them like I did.
  2 Comments
Elif
Elif on 3 Aug 2021
Also, when I tried this code with some other picture it didn't give me any result. What could be the reason for this?

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