An improved spatial-domain lapped transform (SDLT) in a digital media codec uses mismatched relaxed pre-processing filter and aggressive post-processing filter to minimize range expansion while increasing the smoothing effect to reduce blocking artifacts of block transform-based coding. The improved SDLT can further include a range-limiting or clipping operation to limit the range expansion from the pre-processing filter. Additionally, the SDLT can selectively switch pairs of pre- and post-processing filters based on a quality metric.
