Multi-filter analysis of infrared images from the excavation experiment in horizontally stratified rocks

This paper presents a morphological study of the low-resolution and noisy thermogram obtained in the laboratory excavation experiment on the large-scale geological model of man-made horizontally stratified rocks. The developed new image processing algorithm consists of image subtraction, median filter, low-pass alternating-morphological filter, and multi-scale morphological enhancement filter. These filters were used sequentially to process the detected infrared images. In comparison with the old algorithm for thermogram process, the excavation border with changed stress and changed brightness can be distinguished more clearly in the new thermogram sequences. The new algorithm is possible to be applied in processing other low-resolution and noisy thermogram, and the analysis results in this paper are helpful for understanding the pure elastic, the stationary frictional effect and the dynamic frictional effect at the excavation processes.