한국항공운항학회지 (Journal of the Korean Society for Aviation and Aeronautics)
- 제11권2호
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- Pages.33-42
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- 2003
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- 1225-9705(pISSN)
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- 2466-1791(eISSN)
항공기 복합 재료의 비파괴 검사(NDI)를 위한 가변 창 필터를 이용한 초음파 영상 개선
Enhancement of the Ultrasonic Image Using the Adaptive Window Log Filter for NDI of Aircraft Composite Materials
초록
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