Thermography Camera Image Color Scale cropping

Question

Jacob Kalmanovich 2022-6-15

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1741190-thermography-camera-image-color-scale-cropping

评论： Image Analyst 2022-7-28

Hello, I am currently doing a project using Thermography Camera Images. I managed to find a code by @Image Analyst which would allow for me to use these images. I am relatively new to the use of Matlab/Mathworks and am not sure how to properly crop to reach the color bar. Is there a basic code/program I can use that would allow auto-cropping of the photo that would allow me to properly crop the colorbar. I attached the code to the description.Thanks for any assistance

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 = 'Trial1.png'; % Assign the one on the button that they clicked on.
% Get the full filename, with path prepended.
folder = pwd
fullFileName = fullfile(folder, baseFileName);
%===============================================================================
% Read in a demo image.
originalRGBImage = imread(fullFileName);
% Display the image.
subplot(2, 3, 1);
imshow(originalRGBImage, []);
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(originalRGBImage, [], 3); % Useful for finding image and color map regions of image.
% Get the dimensions of the image.  numberOfColorChannels should be = 3.
[rows, columns, numberOfColorChannels] = size(originalRGBImage);
% Crop off the surrounding clutter to get the colorbar.
colorBarImage = imcrop(originalRGBImage, [1, 20, 17, rows]);
b = colorBarImage(:,:,3);
% Crop off the surrounding clutter to get the RGB image.
rgbImage = imcrop(originalRGBImage, [81, 1, columns-20, rows]);
% Get the dimensions of the image.  
% numberOfColorBands should be = 3.
[rows, columns, numberOfColorChannels] = size(rgbImage);
% Display the image.
subplot(2, 3, 2);
imshow(rgbImage, []);
axis on;
caption = sprintf('Cropped Pseudocolor Image');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Column', 'FontSize', fontSize, 'Interpreter', 'None');
ylabel('Row', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo();
% Display the colorbar image.
subplot(2, 3, 3);
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');
drawnow;
% Set up figure properties:
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0.05 1 0.95]);
% 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.
storedColorMap = colorBarImage(:,1,:);
% 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);
% Convert from an RGB image to a grayscale, indexed, thermal image.
indexedImage = rgb2ind(rgbImage, storedColorMap);
% Display the thermal image.
subplot(2, 3, 4);
imshow(indexedImage, []);
axis on;
caption = sprintf('Indexed Image (Gray Scale Image)');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
% Define the temperature at the top end of the scale
% This will probably be the high temperature.
highTemp = 28.9;
% Define the temperature at the dark end of the scale
% This will probably be the low temperature.
lowTemp = 0.9;
% Scale the image so that it's actual temperatures
thermalImage = lowTemp + (highTemp - lowTemp) * mat2gray(indexedImage);
subplot(2, 3, 5);
imshow(thermalImage, []);
axis on;
colorbar;
title('Floating Point Thermal (Temperature) Image', 'FontSize', fontSize, 'Interpreter', 'None');
hp = impixelinfo(); % Let user mouse around and see temperatures.
hp.Units = 'normalized';
hp.Position = [0.45, 0.03, 0.25, 0.05];
% Get the histogram of the indexed image
subplot(2, 3, 6);
histogram(thermalImage, 'Normalization', 'probability');
axis on;
grid on;
caption = sprintf('Histogram of Thermal Temperature Image');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Temperature', 'FontSize', fontSize, 'Interpreter', 'None');
ylabel('Frequency', 'FontSize', fontSize, 'Interpreter', 'None');

4 个评论
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Jacob Kalmanovich 2022-6-20

Trial1.PNG

My apologies, I have attached the image here. The code was originally for a different image. All I did was change the name because, whener I tried to chang the positional information I failed and reverted it back to its original before changes. Any help with this image would be greatly appreciated.

Jacob Kalmanovich 2022-6-20

@DGM

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Answer 1

Image Analyst 2022-6-20

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1741190-thermography-camera-image-color-scale-cropping#answer_989595

If you want you can ask the user to specify the colorbar and image by dragging out a box around them. You can use imcrop or drawrectangle.

See attached drawrectangle demo here in my other answer: https://www.mathworks.com/matlabcentral/answers/1706650-isolate-low-contrast-rectangle-of-known-size-from-image#answer_952410

15 个评论
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Jacob Kalmanovich 2022-6-20

在 MATLAB Online 中打开

Trial1.PNG

My apologies. I attached it to this section. Both the greyscale and the table are needed for my analysis. Thanks again for the assistance.

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 = 'Trial1.png'; % Assign the one on the button that they clicked on.
% Get the full filename, with path prepended.
folder = pwd
fullFileName = fullfile(folder, baseFileName);
%===============================================================================
% Read in a demo image.
originalRGBImage = imread(fullFileName);
% Display the image.
subplot(2, 3, 1);
imshow(originalRGBImage, []);
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(originalRGBImage, [], 3); % Useful for finding image and color map regions of image.
% Get the dimensions of the image.  numberOfColorChannels should be = 3.
[rows, columns, numberOfColorChannels] = size(originalRGBImage);
% Crop off the surrounding clutter to get the colorbar.
colorBarImage = rgbImage = imread('Trial1.PNG');
hFig = figure;
imshow(rgbImage);
hFig.WindowState = 'maximized';
% Ask user to draw rectangle.
button = 'Redraw';
while contains(button, 'Redraw', 'IgnoreCase',true)
	uiwait(helpdlg('Draw a box'));
	% User draws a box.  It exits as soon as they lift the mouse.
	hBox = drawrectangle('Color', 'r');
	
	% Get the coordinates in the form [xLeft, yTop, width, height].
	roiPosition = hBox.Position;
	% Delete the ROI object.
	delete(hBox);
	% and replace it with a rectangle in the graphical overlay.
	hold on;
	hRect = rectangle('Position', roiPosition, 'EdgeColor', 'r', 'LineWidth', 2);
	% Ask user if the rectangle is acceptable.
	message = sprintf('Is this good?');
	button = questdlg(message, message, 'Accept', 'Redraw', 'Reject and Quit', 'Accept');
	if contains(button, 'Quit','IgnoreCase',true)
		delete(hRect);
		roiPosition = [];
		break;
	elseif contains(button, 'Accept','IgnoreCase',true)
		break;
	end
end
% Close down figure.
close(hFig);
b = colorBarImage(:,:,3);
% Crop off the surrounding clutter to get the RGB image.
rgbImage = imcrop(originalRGBImage, [81, 1, columns-20, rows]);
% Get the dimensions of the image.  
% numberOfColorBands should be = 3.
[rows, columns, numberOfColorChannels] = size(rgbImage);
% Display the image.
subplot(2, 3, 2);
imshow(rgbImage, []);
axis on;
caption = sprintf('Cropped Pseudocolor Image');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Column', 'FontSize', fontSize, 'Interpreter', 'None');
ylabel('Row', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo();
% Display the colorbar image.
subplot(2, 3, 3);
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');
drawnow;
% Set up figure properties:
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0.05 1 0.95]);
% 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.
storedColorMap = colorBarImage(:,1,:);
% 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);
% Convert from an RGB image to a grayscale, indexed, thermal image.
indexedImage = rgb2ind(rgbImage, storedColorMap);
% Display the thermal image.
subplot(2, 3, 4);
imshow(indexedImage, []);
axis on;
caption = sprintf('Indexed Image (Gray Scale Image)');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
% Define the temperature at the top end of the scale
% This will probably be the high temperature.
highTemp = 28.9;
% Define the temperature at the dark end of the scale
% This will probably be the low temperature.
lowTemp = 0.9;
% Scale the image so that it's actual temperatures
thermalImage = lowTemp + (highTemp - lowTemp) * mat2gray(indexedImage);
subplot(2, 3, 5);
imshow(thermalImage, []);
axis on;
colorbar;
title('Floating Point Thermal (Temperature) Image', 'FontSize', fontSize, 'Interpreter', 'None');
hp = impixelinfo(); % Let user mouse around and see temperatures.
hp.Units = 'normalized';
hp.Position = [0.45, 0.03, 0.25, 0.05];
% Get the histogram of the indexed image
subplot(2, 3, 6);
histogram(thermalImage, 'Normalization', 'probability');
axis on;
grid on;
caption = sprintf('Histogram of Thermal Temperature Image');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Temperature', 'FontSize', fontSize, 'Interpreter', 'None');
ylabel('Frequency', 'FontSize', fontSize, 'Interpreter', 'None');

Jacob Kalmanovich 2022-6-20

在 MATLAB Online 中打开

Understood. My apologies for that mistake. My expertise with Matlab as you can tell is very minimal and am quite confused. Would this work?

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 = 'Trial1.png'; % Assign the one on the button that they clicked on.
% Get the full filename, with path prepended.
folder = pwd;
fullFileName = fullfile(folder, baseFileName);
%===============================================================================
% Read in a demo image.
originalRGBImage = imread(fullFileName);
% Display the image.
subplot(2, 3, 1);
imshow(originalRGBImage, []);
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(originalRGBImage, [], 3); % Useful for finding image and color map regions of image.
% Get the dimensions of the image.  numberOfColorChannels should be = 3.
[rows, columns, numberOfColorChannels] = size(originalRGBImage);
% Crop off the surrounding clutter to get the colorbar.
rgbImage = imread('Trial1.PNG');
hFig = figure;
imshow(rgbImage);
hFig.WindowState = 'maximized';
% Ask user to draw rectangle.
button = 'Redraw';
while contains(button, 'Redraw', 'IgnoreCase',true)
	uiwait(helpdlg('Draw a box'));
	% User draws a box.  It exits as soon as they lift the mouse.
	hBox = drawrectangle('Color', 'r');
	
	% Get the coordinates in the form [xLeft, yTop, width, height].
	roiPosition = hBox.Position;
	% Delete the ROI object.
	delete(hBox);
	% and replace it with a rectangle in the graphical overlay.
	hold on;
	hRect = rectangle('Position', roiPosition, 'EdgeColor', 'r', 'LineWidth', 2);
	% Ask user if the rectangle is acceptable.
	message = sprintf('Is this good?');
	button = questdlg(message, message, 'Accept', 'Redraw', 'Reject and Quit', 'Accept');
	if contains(button, 'Quit','IgnoreCase',true)
		delete(hRect);
		roiPosition = [];
		break;
	elseif contains(button, 'Accept','IgnoreCase',true)
		break;
	end
end
% Close down figure.
close(hFig);
b = colorBarImage(:,:,3);
% Crop off the surrounding clutter to get the RGB image.
binaryImage = poly2mask(x, y);
measurements = regionprops(binaryImage, 'BoundingBox');
rgbImage = imcrop(originalImage, measurements.BoundingBox);
% Get the dimensions of the image.  
% numberOfColorBands should be = 3.
[rows, columns, numberOfColorChannels] = size(rgbImage);
% Display the image.
subplot(2, 3, 2);
imshow(rgbImage, []);
axis on;
caption = sprintf('Cropped Pseudocolor Image');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Column', 'FontSize', fontSize, 'Interpreter', 'None');
ylabel('Row', 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
hp = impixelinfo();
% Display the colorbar image.
subplot(2, 3, 3);
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');
drawnow;
% Set up figure properties:
% Enlarge figure to full screen.
set(gcf, 'Units', 'Normalized', 'OuterPosition', [0 0.05 1 0.95]);
% 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.
storedColorMap = colorBarImage(:,1,:);
% 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);
% Convert from an RGB image to a grayscale, indexed, thermal image.
indexedImage = rgb2ind(rgbImage, storedColorMap);
% Display the thermal image.
subplot(2, 3, 4);
imshow(indexedImage, []);
axis on;
caption = sprintf('Indexed Image (Gray Scale Image)');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
drawnow;
% Define the temperature at the top end of the scale
% This will probably be the high temperature.
highTemp = 28.9;
% Define the temperature at the dark end of the scale
% This will probably be the low temperature.
lowTemp = 0.9;
% Scale the image so that it's actual temperatures
thermalImage = lowTemp + (highTemp - lowTemp) * mat2gray(indexedImage);
subplot(2, 3, 5);
imshow(thermalImage, []);
axis on;
colorbar;
title('Floating Point Thermal (Temperature) Image', 'FontSize', fontSize, 'Interpreter', 'None');
hp = impixelinfo(); % Let user mouse around and see temperatures.
hp.Units = 'normalized';
hp.Position = [0.45, 0.03, 0.25, 0.05];
% Get the histogram of the indexed image
subplot(2, 3, 6);
histogram(thermalImage, 'Normalization', 'probability');
axis on;
grid on;
caption = sprintf('Histogram of Thermal Temperature Image');
title(caption, 'FontSize', fontSize, 'Interpreter', 'None');
xlabel('Temperature', 'FontSize', fontSize, 'Interpreter', 'None');
ylabel('Frequency', 'FontSize', fontSize, 'Interpreter', 'None');

Jacob Kalmanovich 2022-7-27

Thank you for the assistance Image Analyst. I do have one follow-up question. Is it possible to add code that would allow the program to also find the average and variance of the pixel associated temperatures?