CCTV 自走車已廣泛應用於汙水下水道檢視，倘若檢視影像品質太差，便
無法判讀管線缺失類別。本研究考慮影像的亮度及對比，以量化且客觀的方式
描述檢視影像品質。搜集台中地區十三卷污水下水道檢視影帶，利用所建立的
影像品質量化方式進行分析，可有效描述檢視影帶內的影像品質差異；若影像
品質不佳，則需進行全面或局部重新檢視。未來此方法與CCTV 自走車相關檢
視設備進行整合，檢視過程即時對檢視影像品質作量化描述，將可有效確保汙
水下水道檢視成果品質。

Closed circuit television (CCTV) due to its low setup cost and
technical requirement has been extensively applied in many sewer
inspection cases. Several literatures indicated that good image quality
is prerequisite for accurate interpretation and diagnosis of CCTV
inspection. However, at present a proper evaluation approach for the
image quality of CCTV inspection has not been proposed. In this
paper, an image quality index, in which the luminance and contrast
distortions of between an assessed image and a reference image are
taken into considerations, is proposed and was applied to assess the
image quality of the CCTV images shot for a sewer house-connection
project. The experimental result indicates that image contrast plays a
more important role in CCTV image quality that can be effectively
improved by contrast enhancement. This proposed approach has been