High Efficiency Implementation of Real-Time Median Filtering in Embedded System
Xiaoxia Wang, Dongfang Jiang, Lin Zhiwei · 2010
To meet the requirements of real-time digital filtering in embedded system,a high efficiency digital algorithm small storage occupancy and fast computation speed was proposed for median filtering.In the proposed algorithm,memory applying and releasing operations in data updating were reduced to the lowest limit by using cycle storage structure,which stores newly incoming real-time data to the memory position taken by the oldest data to be deleted.Link-list was borrowed to keep the order of sorted data in the cycle storage structure,which avoided data exchange in sorting procedure,which is necessary in other median filtering algorithms,and improved efficiency of the algorithm by reducing computation complexity of the proposed median filtering to be O(N).Comparative experiment showed that the proposed median filtering algorithm at most took up 37% storage space of the traditional one and ran at least 2 times faster than Matlab medfilt1()function does.