Implementation of algorithm for detection and correction of defective pixels in FPGA

Defect pixels are a common occurrence in digital camera sensors, either resulting from the manufacturing process or developing over time. Though low in quantity, they are very noticeable and can destroy the perceived quality of the images. This paper presents a method for detection and correction of defect pixels in images generated by a Bayer mosaic image sensor. We propose an online and adaptive algorithm, which analyzes the images retrieved from a Bayer array sensor on a pixel by pixel basis. We consider the values of adjacent pixels to determine if the current pixel is possibly defective, which is either confirmed or refuted by repeating the analysis in subsequent frames. For the confirmed defective pixels, interpolation is performed to restore the image quality. The algorithm is implemented on a FPGA logic device, suitable for very high frequency operation required to correct defect pixels in images produced by high definition (HD) cameras.