Crack Image Enhancement of Track Beam Surface Based on Nonsubsampled Contourlet Transform
A hew algorithm of crack image enhancement of straddle-type monorail track beam surface based on nonsubsampled contourlet transform (NSCT) is presented. It is according to the characteristics of different domain in NSCT, and the fractional differentiation can enhance the mid-frequency and retain the low frequency nonlinearly. Then a new enhancement method has been proposed that the smooth sub-band texture of NSCT domain can be enhanced by the fractional differentiation; while in the highfrequency sub-bands of NSCT domain, each pixel of high-frequency sub-bands is divided into strong edge, weak edge and noise on the basis of direction sensitivity characteristics, then the weak edge can be enhanced nonlinearly, strong edge be retained, and noise be removed. Experimental results show that the method proposed in this paper have greatly improved visual effects and larger contrast improve index (CII) as compared with wavelet transform, and the enhancement effect is very good.
crack enhancement nonsubsampled contourlet transform fractional differentiation
Chunhua Guo Tongqing Wang
The Key Laboratory of Optoelectronic Technology & Systems of the Ministry of Education,Chong Qing University, Chong Qing, 400030
国际会议
无锡
英文
333-341
2010-09-17（万方平台首次上网日期，不代表论文的发表时间）