Design Of A Bilateral Filter For Color Image Denoising
Alin Mary Varghese Baby · i-manager s Journal on Digital Signal Processing · 2015
Bilateral filtering provides two advantages such as noise reduction[3] and detailed preservation. This is done by two components presented in the bilateral filter. They are photometric filter and geometric filter components. Photometric filter component is a non-linear filter component which preserves the details of the image. The geometric filter is a linear filter component which reduces the noise. Thus by using a bilateral filter one could reduce the noise present in an image while preserving the details of that particular image. Here a FPGA design architecture of the bilateral filter is presented. The main advantages of this design is capability of real time processing. The external image buffer is not necessary, according to the data flow. The internal clock frequency could be raised, data could be grouped and separate pipelines could be assigned through them and finally effective and economical utilisation of resources is obtained. This design is applicable in projections of computer tomography[4]. 1. Bilateral Filter The bilateral filter[1] consists of a domain filter and a range filter. The nearby pixel values are averaged by the domain filter which acts as a low pass filter. The edges are preserved by the non-linear component range filter. It averages the similar pixel values regardless of their position in the filter window only. The operation of bilateral filter is given by :