FPGA design and implementation of edge enhancement by using 3×3 mask filter

Abstract

This paper proposes a method to implement an image filtering module by using 3×3 mask on FPGA. The 3×3 mask filter module has an advantage of minimizing a usage of memory and a propagation delay from input to output. Depending on coefficient value of 3×3 mask filter module, we can acquire several image processing effects such as mean filtering, median filtering, and edge enhancement. When we applied Laplacian filter to enhance sharpness of an image by using the 3×3 mask filter module, not only edges components but also noise components of an image were enhanced by Laplacian filter. So we propose an adaptive edge enhancement by using Laplacian filter that is a method to enhance edge components except noise components of an image by analyzing a variance of pixel data in 3×3 mask. We applied the adaptive edge enhancement by using Laplacian filter to an infrared camera and conducted an experiment about its effect. The experimental result proves that the proposed method is effective to implement the edge enhancement of an image with minimum usage of memory in real time.