2. Image analysis techniques

2.1 Presentation

Whereas in the visible spectrum, two-dimensional photosensitive targets were developed fairly early on, enabling television images to be obtained by purely electronic means, in the thermal infrared, whether in the 3-5 µm or 8-12 µm band, the only detectors available for a long time were those grouped in very small numbers in relation to the number of points in an image. The main reasons for this are, on the one hand, the lower energy (hν) of photons in the infrared, which requires detectors to be cooled, and, on the other hand, detection materials (InSb, HgCdTe) that are more complex to manufacture and more fragile than Silicon. Two-dimensional infrared targets with sufficient thermal resolution only began to reach maturity in 1995.

Initially,...