*3.10. Summary of Techniques for Identifying Cracks and Their Accuracy in the Literature Review Works*

The authors of the works, which have been included in the literature review, stress the universality of individual methods, as they can be applied to virtually any engineering problem aimed at identifying surface linear structures. The presented crack identification techniques have been developed mainly to apply to the surface of cement composites, practically in every application, i.e., bridge structures, reinforced concrete tanks, floor and wall structures, structures in nuclear power plants, dams, etc. The second group of application that stands out is road surfaces, both concrete and asphalt.

Table 2 synthetically lists the types of techniques used to detect surface cracks in cement composites embedded in various types of structures, with references to literature items covering the scope of this literature review. In most cases the developed cracks detection algorithms are often a combination of many techniques, so the list also includes those methods which are not discussed in detail. In addition, the levels of accuracy of cracks identification obtained by individual researchers are presented, based on the literature survey.


**Table 2.** A summary of the cracks identification techniques and their accuracy, with literature references.

Apart from methods closely related to the computer image analysis, there are also other methods of cracks detection, e.g., infrared thermography, x-ray tomography or acoustic emission.
