Picturetel Corporation

John C Sievers

John E Bruder

A method and apparatus for selectively pre-filtering signal representations of images representing data to be transmitted and substantially maintaining the frame rate of transmission by reducing the number of expected bits needed to transmit the selected block portions of an image frame. The pre-filter uses the quantizer state value representative of the number of expected bits required for each block portion of the image as well as a weighted energy error value based on the preselected coding method of the block of the image being transmitted to determine a level of prefiltering required. The prefilter, for example, may be a multi-tap filter having a center tap and outer taps with amplitudes based on the quantizer state and weighted error energy values.

Growing community of inventors

Wakefield, MA, United States of America

John C Sievers