US Patent 7782954 Scan patterns for progressive video content

Tools and techniques for applying scan patterns during encoding and decoding of progressive video are described. For example, a video decoder entropy decodes transform coefficients in a one-dimensional array and scans the transform coefficients into a block according to a scan pattern. The block is 8×4, and the scan pattern biases the vertical direction for at least the lowest frequency AC coefficients in the horizontal and vertical directions. Or, the block is 4×8, and the scan pattern biases the horizontal direction for at least the lowest frequency AC coefficients in the horizontal and vertical directions. A corresponding video encoder applies the scan patterns to scan transform coefficients from blocks to one-dimensional arrays.