Thermal Imaging

Thermal images, or thermograms, are actually visual displays of the amount of infared energy emitted, transmitted and reflected by an object.
A thermal image camera is capable of performing algorithms to interpret data and build an image. Whilst this gives an idea of the temperature at which the object is operating, the camera is actually using multiple sources of data based on areas surrounding the object to determine that value rather than the temperature itself.
The formula for this is as follows:

Incident radiant power - emitted radiant power + transmitted radiant power + reflected radiant power

Unfortunately, this is not actually a thermal image just an out of focus image (I used completely the wrong film speed) of our local Turkish restaurant. It has lights on the outside of the building which change through a spectrum of colours - red, orange, blue, purple and pink. I still like the effect though!