Abstract: Image data in an initial color format (e.g., subsampled YUV9 data) is color converted to a selected RGB16 color format by executing compiled computer program code. The same compiled computer program code can be used to convert the image data in the initial color format into image data in any of two or more different RGB16 formats. In a preferred embodiment, lookup tables (configurable during run-time processing) are used to make the color conversion processing more efficient. The selected RGB16 color format can be changed during run-time processing, in which case certain lookup tables are reinitialized for the newly selected RGB16 format.

Abstract: A video system that determines an indication of interpolation errors for each of a set of available subsampling modes for encoding a target video frame that contains a set of pixel data values corresponding to an image scene is described. Each available subsampling mode provides a differing degree of subsampling on the target video frame. The video system determines a selected subsampling mode from the available subsampling modes such that the selected subsampling mode provides an attainable degree of subsampling with minimal loss in image quality.

Abstract: Input image data is stored in an interleaved format, in which data from two or more blocks are stored in an alternating fashion. Motion compensation is performed on the interleaved data by applying motion vectors to the appropriate data to generate different blocks of motion-compensated image data in the interleaved format. In one embodiment, the input image data are reference data and the motion compensation generates motion-compensated prediction data used during video compression processing. The present invention enables other steps in such video compression processing (e.g., inverse block transform and motion-compensated addition) to be implemented efficiently in pseudo-SIMD fashion without having to convert image data back and forth between the interleaved format and conventional block order format.

Abstract: A video system renders an intra versus inter encoding decision for a digitally sampled target video frame of an image scene by subdividing the target video frame into cells. Each target cell contains a set of pixel data values corresponding to the image scene. The video system determines a vertical gradient measure for each target cell, and determines an error measure between each target cell and a corresponding predicted cell of a preceding video frame. If the vertical gradient measure for a target cell is high in comparison to the error measure, then the target cell is encoded relative to the corresponding predicted cell. If the vertical gradient measure for the target cell is low in comparison to the error measure, then the target cell is encoded independent of the predicted cell. The vertical gradient measure is optimized for an intra cell encoding technique that encodes differences between pixel data values in adjacent rows of the target cell.

Abstract: A reference characterization characterizes the relationship between frames encoded using a first encoding process and frames encoded using a second encoding process for a variety of frames. A previous frame is encoded using the first encoding process and the encoded previous frame is characterized. A current frame is encoded using the second encoding process, wherein the current frame is encoded in accordance with the reference characterization and the characterization of the encoded previous frame.

Abstract: A cell of an image is segmented into two or more subcells. According to one embodiment, the nullity of each of the subcells is classified and the cell is encoded in accordance with the nullity of the subcells. According to another embodiment, the quantization level of each of the subcells is classified and the cell is encoded in accordance with the quantization levels of the subcells.