Weighted median filters: An analog implementation

•Proposed cell can perform weighted median extraction applying different window masks.•Cell works with 5-inputs for 5-pixel filtering (cross fashion) for image processing.•WMF preserves simplicity of previous works and achieves the expected performance.•Low power consumption of 180 nW compared with other median extractor implementations.•Median cell requires only 0.013mm2 (subthreshold operation).

The feasibility of implementing analog CMOS VLSI weighted median filters for image and signal processing is discussed. The proposed weighted median filter uses a transconductance comparator as a basic cell, where the output saturation current is used as the weight parameter in the median filter. Experimental results of the proposed analog weighted median filter for an ON Semiconductor 0.5 μm technology through MOSIS fabricated prototype are shown.