FPGA Based Multi-shell Filter for Hot Pixel Removal within Colour Filter Array Demosaicing

Modern cameras have an image sensor with millions of pixels, among which some of them are inevitably defective (known as hot pixels). Moreover, the number of hot pixels will increase with ageing. colour filter array (CFA) demosaicing will result in colour artifacts caused by these hot pixels. Such artifacts are virtually impossible to remove after demosaicing. In this paper, we propose two effective filter structures for removing low and high density hot pixels within CFA demosaicing for efficient implementation on FGPA for real-time processing. It has been shown that our proposed filter structures are able to remove hot pixels effectively with minimal colour artifacts while preserving image details.