Introduction to Crack Image Analysis System
System architecture：mainly includes single image processing module and multi-image batch processing module
Fig. 1 Software architecture of CIAS-NJU
Main function of system：
（1）Image Preprocessing: In order to accurately identify and extract cracks, the image needs to be processed first. CIAS system can quickly separate cracks from soil clods and other miscellaneous information, repair and strengthen cracks reasonably, and facilitate subsequent quantitative processing. The pre-processing functions mainly include image gray-scale, binarization, denoising and so on. It should be emphasized that for a variety of complex crack images, CIAS system provides four binarization methods for choice, as well as fixed-point impurity removal, crack bridge and other functions, so as to facilitate users to obtain satisfactory preprocessing results.
Fig. 2 Image processing flow of crack
（2）Soil Block Identification and Quantification: This mainly includes the identification of soil blocks and the extraction of soil block geometric morphological parameters. The CIAS system can quickly quantify multiple parameters such as soil block area, perimeter, number, area ratio, shape coefficient, size factor, equivalent side length, and equivalent diameter.
（3）Crack Identification and Quantification: Fracture identification and quantification are the core functions of the CIAS system, enabling functions such as fracture recognition and extraction, graphical display, morphological parameter statistics, and quantitative analysis. Quantitative parameters related to fracture geometry include fracture area, length, width, number, angle, fractal dimension, number of intersection points, surface fracture rate, and probability density function. It is important to note that to make fracture identification and quantification more accurate, the CIAS system can perform smoothing and skeletonization processing on fracture images, meeting the quantitative requirements of complex fracture networks.
（4）Batch Processing of Multiple Images: The CIAS system is capable of rapid batch processing of multiple fracture images, which is one of the main features of the system. It greatly reduces the complexity of operations and provides users with a pleasant experience. To meet the needs of different users, batch processing includes two sub-modules: step-by-step batch processing and fully automatic one-click batch processing.
（5）Data Output and Saving: To facilitate users' subsequent data analysis, all fracture quantification parameters obtained through the CIAS system can be saved as txt and excel files, and all intermediate process images can also be saved at any time.
Fig. 3 CIAS software quantified crack image example
Instructions - Video explanation
If you want to use CIAS, please contact Professor Chao-Sheng Tang for the software and HD video explanation.
（e-mail: tangchaosheng@nju.edu.cn）
