Adaptive noise reduction and image sharpening for digital video compression

This paper presents a framework of digital video preprocessing for digital video compression. The purpose of this preprocessing is to reduce the noise and thus improve the video compression efficiency. A four stage processing system has been proposed. The first process is a median filter to remove the 2D impulse noise. The second process is a 2D spatial filter that is controllable by the video encoder parameters. The third process is an image sharpening operation to enhance the image resolution or details so that the decoded video from the encoded bitstream still gives high resolution content. The last process is a recursive temporal filter that is used to reduce the temporal noise. The recursive filter is designed to adapt to the video content so that high quality temporal filtering is achieved.