**3.3. Usage of IR-based technologies in photography techniques**

In the following years, especially after the year 2000, the IR image capture conversion kits of digital cameras began to be developed. In 2006, the first professional digital camera, which

**3. Usage of IR-based technologies in daily life and reflections on forensic**

To date, IR-based technologies are a component of daily life. This technology is used in many applications in automotive technology, the petroleum industry, photography techniques, the

In terms of driving safety, IR-based technology comprises a method that may be used routinely in the future. Currently, it is used by a limited number of companies. One of these systems is based on NIR integration on the basis of existing head-up display systems in vehicles. This system aims to warn of car drivers using a screen in connection with a NIR camera mounted in the front bumper. The NIR camera will distinguish cars, people, animals and other objects on the road, especially at night, based on their heat. One reason for the lack of routine use of this system is that IR cameras transfer images from only 100 meters [17]. It has been indicated that the IR cameras may be used for passenger safety and comfort. IR cameras enable data to be obtained, such as whether there is a seat passenger and the estimated weight if there is a passenger, especially in a bus. In light of these data, equipment based on NIR and IR may be added to vehicles, such as an adjustment system for the air bag pressure according to passen‐ gers, indicators regarding accurate issuance of the seat belt warning, passenger-oriented climate control systems, a radar based mass movement sensor for automotive security applications, a driver monitoring system that warns a fatigued driver to pull over and rest, advanced driver assistance systems, including features such as a lane departure warning and switching between autonomous and manual driving mode and systems that disable the vehicle in situations such as drunk driving [17–20]. These systems that improve vehicle safety will cause a decrease in the number of traffic accidents, as well as the number of deaths and injured individuals in traffic accidents. Thus, this system will be an important service for preventive

One key area that utilizes IR has been the refinement of petroleum products. In the production of rubber, relatively simple techniques have been used for the analysis of C4 hydrocarbons. NIR spectroscopy has been used for petroleum refining, especially for petrochemicals and polymers. The major advantages of NIR spectroscopy include its fast, non-destructive and easy approach to extend to online analysis in conjunction with optical fibers. Based on these advantages, oil companies have used IR spectrophotometry and Raman spectrophotometry

security sector, agricultural inspection, the forestry sector and medical applications.

**3.1. Usage of IR-based technologies in automotive technology**

medicine, which is an important task in forensic science.

for the online control of product quality [21, 22].

**3.2. Usage of IR-based technologies in petroleum industry**

was developed using ultraviolet (UV) and IR technology, was introduced [16].

**science**

100 Forensic Analysis - From Death to Justice

Each object that has a temperature above absolute zero (0° Kelvin, −273°C) emits radiation in the IR region [6]. The IR spectrum is broad from the visible radiation spectrum. IR radiation is related to object temperature, and the IR radiation emitted by objects increases when the object temperature increases. This IR radiation ensures the visibility of objects without lighting. In thermographic imaging, emission, transmission and reflection occur via heat transfer between the camera and the object [25]. A thermographic camera detects changes in temper‐ ature as a result of this radiation in the range of the electromagnetic spectrum from 0.9–14 μm [6, 13]. On the basis of thermal camera imaging, the reflected differences in temperature transfer the image [6]. Several conditions are necessary to create the images of thermal cameras. Thermal camera imaging may be used for objects that have different heat conductivities, objects that have the same emissions but different heat, objects that have the same heat but different emissions, objects that have radiation reflection or the same objects under different weather conditions [14]. The non-contact IR thermography (IRT) technique comprises a nondestructive inspection method. It uses IR irradiation to identify and record the thermal pattern and temperature that spread across an object surface. This equipment converts temperature by sensing IR radiation, and it provides the converted image of this distribution [6].

Typical IR cameras include semiconductors to detect IR energy from the target object and cooled detectors. The typical IR camera signal processing mechanism may be summarized as follows: (1) the image is created using radiation in the IR wavelength range by the optical system; (2) radiation detected by the thermal detectors is converted into electrical signals via the thermal detectors; (3) some systems require the scanning mechanism, whereas other systems do not require, in general, a large detector array to completely cover the field of view of the camera; and (4) an electrical signal is converted to a video signal by the electronic processor, and an image is formed by transmitting the video signal to the display unit [6, 26].

In general, IR cameras use a single sensor, and they do not differentiate different wavelengths of IR radiation. Color is not significant in areas outside the visible wave lengths. Color IR cameras have a more complex structure. In these cameras, the colors used in the camera structure are pseudo-coloring, which demonstrate changes in the incoming signals [6].

IR cameras with uncooled detectors were implemented after 1990. In the following years, the prices of IR cameras steadily decreased, and their usage was widespread as the parallel of the rapidly developing technology [26]. IR imaging is an important technique used in forensic science, especially crime scene investigations. The use of these techniques in forensic science is described in detail in the section under "Usage of IR-Based Technologies in Forensic Sciences".
