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

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Blaxe 05 on 5 Feb 2015
Edited: DGM on 30 Nov 2021
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 :

Mohammad Haghighat on 5 Feb 2015
temperature = 28.4 + intensity*(36-28.4)/255
DGM on 30 Nov 2021
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.

### More Answers (2)

NIVITHA S on 1 Jul 2015
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

monika SINGH on 15 Apr 2019
sir is there any relation between gray level and temperature??