Abstract: A method for detecting dropouts in digital data transferred over a bus from a digital data source to a computer system. Each address in the computer system buffer memory is initialized to a selected code value known not to exist in the data to be transferred. After sequential transfer of data to the buffer memory, the presence of the selected code value in the buffer memory indicates that a dropout occured.

Abstract: A method and system for combining a set of n still image frames into a single reduced noise still image. The invention reduces visible noise, along with some television color artifacts, in still images captured from a video stream by combining data from multiple video frames. Each frame comprises an XY array of picture element (pixel) data. In the preferred embodiment, each pixel includes data defining an intensity level as well as color values. A weighted average of several frames of video is taken to generate a single still output frame. The weighting is determined adaptively in order to reduce inter-frame motion artifacts. The resulting output has substantially less visible noise than a simple unweighted average. The algorithm is much faster and simpler to implement than true multi-pixel motion estimation, which is not really necessary in a series of nominally-still images.

Abstract: An adaptive method and system for processing luma and chroma signals from lines of a video signal. The invention includes an adaptive comb filtering algorithm that determines whether to average lines of video data based on the signal content. If two lines are dissimilar, a simple notch/bandpass system is used. The invention provides improved adaptive comb filtering performance at vertical transitions between high-luminance-detail areas and between other areas such as solid colors or flat gray or white fields by dynamically determining whether to average the chrominance information of the current video line with the chrominance information of the previous line, next line, both of such lines, or neither of such lines.