Abstract: A machine independent high resolution digital screen recorder provides high quality video displays with manageable storage capacity and bandwidth. The screen recorder includes an analog to digital frame grabber for converting the high resolution video signal that modulates a video display into RGB sequences of digital frames. A video compression unit separates the high and low variance portions of the digital frames, encodes them with respective lossy and lossless compression algorithms and stores them in a mass storage device.

Abstract: A method for specifying a video window's boundary coordinates directly from a multi-color video signal to separate the signals high and low variance components. The method converts the analog multi-color video signal into respective color sequences of digital frames and transforms them into another sequence of digital frames that represent the intensity of the multi-color video signal. The method generates difference frames between successive transformed intensity frames and computes a row activity measure and a column activity measure from at least one of the difference frames. The video window's approximate boundary coordinates are determined from said row and column activity measures.