Abstract: An enhanced video data compressor has a composite video signal decoder that changes the state of a field identification signal in response to a vertical interval indicator in composite video data which is in a digital video format. Thereafter a vertical timing pulse is generated to prepare a compression encoder to acquire data. By counting lines from the vertical timing pulse the decoder sets a horizontal timing signal at a one macroblock line interval prior to active video data so that the compression encoder acquires video data from the vertical interval as well as active video data. At the end of each field the acquired data is processed by the compression encoder to produce compressed video data.

Abstract: A variable coefficient, non-separable spatio-temporal interpolation filter is used to deinterlace an interlaced video signal to produce a progressive video signal. The interlaced video signal is input to a video memory which in turn provides a reference and plurality of offset video signals representing the pixel being interpolated and spatially and temporally neighboring pixels. A coefficient index, transmitted with the interlaced video as an auxiliary signal, or derived from motion vectors transmitted with the interlaced video, or derived directly from the interlaced video signal, is applied to a coefficient memory to select a set of filter coefficients. The reference and offset video signals are weighted together with the filter coefficients in the spatio-temporal interpolation filter, such as a FIR filter, to produce an interpolated video signal.

Abstract: Chrominance resampling for color images to produce an upsampled chrominance signal from a subsampled chrominance signal uses luminance to detect edges in the color image. The detection of edges produces an Index signal which is used to select a particular one of a plurality of lowpass filters for filtering a chrominance signal expanded from the subsampled chrominance signal. For interlaced video signals a field/frame decision is made based upon relative motion between the fields of each frame, which decision is input to the filter selection process. The resulting chrominance samples in the upsampled chrominance signal are offset to co-site the samples with the corresponding luminance samples at the output.

Abstract: A bit rate control mechanism for a digital image or video compression system estimates a complexity parameter for a current picture, or block of samples, of a video signal as a function of parameters for a prior picture of the video signal, which parameters include a bit rate. From the complexity parameter a quality factor for the current picture is determined and applied to a quantizer to compress the current picture. A complexity pre-processor may also be used to detect scene changes in the video signal prior to estimating the complexity parameter. If there is a scene change detected, then the rate control mechanism is reset prior to estimating the complexity parameter for the first picture in the new scene.

Abstract: Fractional pixel motion estimation of video signals is performed by comparing a block of pixels from a current image of the video signal with a plurality of displaced blocks within a search window from a previous/future reference image of the video signal via a distortion function. The displaced block from the reference image that produces the minimum value for the distortion function provides a center pixel. A general surface is fitted around this center pixel so that it equals the distortion function at each integer pixel location surrounding the center pixel. The distortion function for the fitted surface is estimated for fractional pixel locations, and the motion vector corresponding to the minimum value for the fractional distortion function is selected for transmission as part of the compressed video.