Soiled banknote fitness determination based on morphology and Otsu's thresholding

Sanghun Lee, Sangwook Baek, Euisun Choi, Yoonkil Baek, Chulhee Lee

Abstract: This paper presents a soiled banknote determination method based on morphology and Otsu's thresholding method. Using morphology, a texture image was extracted with selective morphological closing operations, and the soiling level was estimated by averaging the pixel intensities of the texture image. Next, the Otsu threshold was calculated and used to determine whether each pixel was a foreground or background pixel. Then the soiling level was estimated using the difference between the averages of the foreground and background pixels. We used the weighted sum of the two estimated values as a soiling level measure. The proposed method showed good performance on Euro and Russian banknotes.