Abstract: Static fade in a digital video image is detected. A difference in luminance intensity is determined for correspondingly positioned pixels in successive images. A variance in the difference is determined, and then normalized according to a mean squared value of the difference to provide a fade index J.sub.n. The fade index is compared to a fade threshold, e.g., 0.9, to determine if a fade is indicated. Optionally, a check may be made to verify that a static fade is indicated by comparing the mean squared value of the difference to a motion threshold. The technique is suitable for both frame mode and field mode video sequences. When the digital images include field mode video, where each image has first and second fields, a fade index is determined separately for each field, and an overall fade index is obtained by averaging the fade indexes from each field. A scheme for detecting static fade on a macroblock by macroblock basis is also presented.

Abstract: A current pixel of a video image is adaptively filtered to provide stronger filtering when there is a high likelihood that noise is present. Weaker filtering is provided when the presence of a color and/or brightness edge is likely in the video image. Each pixel has luminance and chrominance amplitude values. In a filtering method, a current pixel is intermediate to first and second pixels in the video frame. Difference signals are determined based on the amplitude difference between the current pixel and first and second adjacent pixels. A plurality of available filters provide successively stronger filtering of the current pixel amplitude. One of the filters is selected for filtering the current pixel according to the difference signals. Secondary difference signals which indicate the amplitude difference between the current pixel and pixels which are adjacent to the first and second pixels are also considered in the selection process.

Abstract: A video encoder control system and method are disclosed for controlling a video encoder using a processor having a multiple field delay circuit for delaying input video data by a predetermined number of frames, and a statistics generator for generating statistics from the video data to control the encoder. The statistics generator calculates a sum of absolute values of field differences between pixels, with the sum used for detecting a redundant field, for generating a film flag, and for controlling the encoder using the film flag. The statistics generator calculates averages of blocks of pixels, and a fade detector uses the averages for detecting fades between successive frames to generate a fade flag to control the encoding. The rate controller responds to the statistics to change the resolution of the encoding of successive frames. The processor outputs the film flags, scene change flags, and fade flags to the rate controller to control the encoding of the delayed video data.