Extraction method of borehole panoramic image from televiewer video

Compared with the panoramic borehole imaging system,the forward borehole camera can only record videos. Through statistical methods,a qualitative description of borehole can be obtained,while a quantitative analysis cannot be done. To solve this problem,an approach,which can transform the videos from forward borehole camera into panora- ma images,was proposed. The concept of equivalent circle in the video screenshots was presented,which equals to the corresponding borehole in-situ information. Then a coordinate transformation formula was derived to convert circular images to rectangular ones. Finally,a borehole video of N3 -7 working face in Changcun Coal Mine was successfully transformed into panoramic images by utilizing this method. After that,the panoramic images were processed by using the HSL color space. One panoramic image was analyzed,and the dip angle and tendency of the crack faces in-situ were obtained. Quantitative analysis can be taken by employing this method,and it can be used in any forward bore- hole camera system.