A modified approximation of 2D Gaussian smoothing filters for fixed-point platforms

Gaussian smoothing filters are commonly used in various image processing applications to reduce the noise level in an image. The filters are particularly popular in edge detection algorithms because of their ability to smooth false edges and improve the edge detection performance. When implemented on a fixed-point computational platform, the filter coefficients are rounded and the implemented filter becomes a rounded approximation of the original one. In those implementations, system designers must balance between signal integrity and the hardware size they can afford in a particular design. In this work, we suggest a new “modified” method to approximate the coefficients of a 2D Gaussian filter. When implemented on a Field Programmable Gate Array (FPGA), the modified approximation filter is shown to generally deliver higher signal quality than its traditional “rounded” counterpart without any increase in the required resources.