A Searching and Enhancement Alogorithm for Shadow Areas Using Histogram and Correlation in Fourier Domain

Searching and enhancement of shadow area in the satellite imagery is one of growing interest because of new possible needs of application in this field. This paper proposes an algorithm to search and enhance the shadow areas caused by buildings such as apartments which are very common in Korean satellite imagery. The proposed searching algorithm makes use of characteristics of histogram of images in the spatial domain and also uses the fast Fourier transform and correlation in Frequency domain. Further, the enhancement algorithm is only applied to the shadow areas searched and preserves the areas which are naturally dark.