thermal image processing to get the temprature on each pixel

i installed a darvi camera and taken the thermal images from this camera. i get the image in jeeg format. i want to calculate the tempratue of eache pixel of that image, i want ta calculate emistivity, region of interset. is it possible in matlab

[yanqi liu]

yes，sir，may be use some image segment method，if possible，may be upload some image to analysis

[Neha Thakkar]

i atteched the image. actually m new in matlab coding. i want to extract the bull body temprature on each roi and environment temprature from this images.

Answer 1

[DGM]

Image Analyst has a number of examples

This is the current version of the demo he posted below:

https://www.mathworks.com/matlabcentral/answers/1923970-background-color-correction-of-a-rgb-picture#answer_1193820

... and these are some of the earlier answers

https://www.mathworks.com/matlabcentral/answers/320467-i-need-to-convert-rgb-image-into-thermal-image-for-temperature-detection-of-human-being-without-usin

https://www.mathworks.com/matlabcentral/answers/384579-thermal-camera-image-processing

https://www.mathworks.com/matlabcentral/answers/1741190-thermography-camera-image-color-scale-cropping

Answer 2

[Image Analyst]

See attached demo. I had been using hard coded coordinates for the colorbar since, once known, they won't change for that particular camera. However so many people seem to be unable to figure out what coordinates the image and color bar are at that I decided to have the user draw a box around each. I also adapted it to handle either vertical or horizontal colorbars.

[Neha Thakkar]

Thankx for resolving this issue.But my mentor want a scroll bar is moving at each pixel on that image and showing its temprature on that pixel. i have seen a demo package https://github.com/detecttechnologies/Thermal-Image-Analysis#save-data. but it not working properly.

[Neha Thakkar]

sorry, for another Question. i am unable to run this function

roiPosition = GetRectangularROI('Drag a box out over the portion of the image you want to analyze.'); because my image is moving or expanded in figure console nd i am not able to cut the region of intreset from this image. can you please explain this solutions of this problem.

[Image Analyst]

I don't know how to have a scroll bar for every pixel. If you want a "live" readout of the temperatures, look at the status bar near the bottom that gives you the values as you mouse around over the image.

I've put a newer version in my File Exchange:

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

I don't know why you can't use GetRectangularROI - maybe it's because you have a version older than r2018b. You can substitute imcrop for drawrectangle. imcrop will work with antique versions.

[Neha Thakkar]

actully i m using the matlab online nd i am not able to find out this GetRectangularROI() function, when i m using the drawrectangle r1 = drawrectangle('Label','Row','Color',[1 0 0]); while i m executing the next command its giving me error.

imageRow1 = round(r1(2));

Index exceeds the number of array elements.

Index must not exceed 1.

i m doing something wrong.

[Image Analyst]

Then just hard code in the rows and columns that you know the image and colorbar cover. Or ask Mathworks for a free 30 day trial version.

[Neha Thakkar]

hey thankx for the code.i succesfully implement this code. but i am not able to figur it out the temprature on each pixel the histogram shows the frequency and temprature. i want to know the temprature of bull different body parts like, Teats fore udder, Naval Flap and environment temprature.

[Image Analyst]

@Neha Thakkar that's what the temperature image, "thermalImage", is. Just mouse around over the image and see the temperature at the bottom of the GUI. Or you can double click thermalImage in the workspace to have it popup in a spreadsheet like form inside MATLAB. If that solves it, can you click the "Accept this answer" link? Thanks in advance. 🙂

[Neha Thakkar]

yes, but whin i m moving around the mouse over it, its not showing anything like temprature i have to extract the informations from this image or you can guide me about the instering image in gui of matlab

[Image Analyst]

That won't because it's not using my program. It looks like you're just using some interactive MATLAB function to read in an RGB image. You need to do it from my program. You can either watch the GUI as you mouse around or specify a list of (row, column) coordinates to thermalImage array in the code.