How to map certain temperature range into 0-255 gray scale image (thermogram) ?? Please advice...

I need to analyse the temperature variation on the facial area which i already got the thermal images in gray scale uint8 format. The range of the temperature map on the images are between 28-36 degree celcius. So my question is how do i relate the intensity of the temperature with 0-255?? I'm using Flir camera for this research. Please anyone help me...thanks a lot...
here is a sample of the image :

 Accepted Answer

temperature = 28.4 + intensity*(36-28.4)/255

5 Comments

hiii Mohammad Haghighat...thank you for your kind reply :)..now i can proceed..
Hey... I hv a thermal image which pixels are mapped in range 17-42 degree celsius and i wanted it to map pixels of this image in range of 25-50 degree celcius ?? do u hav any idea how to do dis ???
What is the literature behind this formula?
temperature = 28.4 + intensity*(36-28.4)/255
thanks in advance.
There is no literature. The constants are not part of some general law relating image intensity to temperature. It's merely observation based on the colorbar embedded in the provided image.
Since black maps to 28.4 degrees and white maps to 36 degrees, the rest is just a linear rescaling operation. It's assumed that the image data lies within the range [0 255].
Note that this only applies because the image is a thermal image wherein the map range is given and the map can be assumed to be linear. This doesn't apply to grayscale images taken with conventional visible-light cameras.

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More Answers (2)

i have a floor diagram , i just want to show temperature variations in different places .can u please suggest some ideas for proceeding with this concept

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Asked:

on 5 Feb 2015

Edited:

DGM
on 30 Nov 2021

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