A parameterizable digital-approximated 2D Gaussian smoothing filter for edge detection in noisy image

This paper describes a 5times5 window-based, power-of-two approximation algorithm for 2D Gaussian smoothing filter and its generic hardware reference design. With a small change in standard deviation sigma, the Gaussian smoothing filter is able to provide different levels of smoothing and noise reduction capability, which is highly desirable in the early stage of an image processing flow. By using power-of-two terms, the digital-approximated 2D Gaussian filter can be implemented by simple hardware shifters. A hardware reference design is also proposed to achieve such functionality. Experiments in using the proposed filter with an existing edge detection algorithm show the flexibility and effectiveness of the proposed smoothing mask. The synthesized hardware of such combination shows a 200MHz high operating frequency under UMC 0.18mum technology, which proves the proposed filter is able to achieve the real-time high frame-rate and high-resolution video processing requirements