Wavelet Analysis on Crack Image of Coal Mining Roof

Appling an image edge detection algorithm based on the wavelet transform to crack image of roof in coal in the paper. Digital image processing technology was introduced to the research on crack image of roof rock in this paper, which is independent from lithology and mechanical characteristics of certain rocks. Firstly, the crack image would be divided into different frequency band by wavelet transform, and would be filtered by frequency characteristic. At last, the edge extraction of the image completed.