- 항공기 복합 재료의 비파괴 검사(NDI)를 위한 가변 창 필터를 이용한 초음파 영상 개선
- ㆍ 저자명
- 홍교영,홍승범,Hong. G.Y.,Hong. S.B.
- ㆍ 간행물명
- 한국항공운항학회지
- ㆍ 권/호정보
- 2003년|11권 2호|pp.33-42 (10 pages)
- ㆍ 발행정보
- 한국항공운항학회
- ㆍ 파일정보
- 정기간행물| PDF텍스트
- ㆍ 주제분야
- 기타
In this paper, we propose an enhancement of the ultrasonic image for non-destructive inspection of aircraft composite materials. The ultrasonic images are corrupted by a speckle noise which has the characteristic of granular pattern noise and is in all types of coherent imaging systems, the signal independent and multiplicative noise. In this paper, we derive a filter, called the AWLF(Adaptive Window Log Filter), from the nature of the speckle. The filter is made of the MEAN Filter in the edge region and Log Filter in the flat or noise region. To make a distinction between edge and flat region, we calculate the inclination around the local window instead of computing the local statistics of pixels such as local mean ${ar{M}}$ and standard deviation ${sigma}_s$. According to the obtained region, edge region is performed by the mean filter and flat region by the Log filter. Performance of the proposed filter is evaluated by the Enhanced Factor$(F_e)$ and the Speckle Index(SI).