This invention introduces a class of multi-band linear phase lapped
biorthogonal transforms with fast, VLSI-friendly implementations via
lifting steps called the LiftLT. The transform is based on a lattice
structure which robustly enforces both linear phase and perfect
reconstruction properties. The lattice coefficients are parameterized as
a series of lifting steps, providing fast, efficient in-place computation
of the transform coefficients as well as the ability to map integers to
integers. Our main motivation of the new transform is its application in
image and video coding. Comparing to the popular 8.times.8 DCT, the
8.times.16 LiftLT only requires 1 more multiplication, 22 more additions,
and 6 more shifting operations. However, image coding examples show that
the LiftLT is far superior to the DCT in both objective and subjective
coding performance. Thanks to properly designed overlapping basis
functions, the LiftLT can completely eliminate annoying blocking
artifacts. In fact, the novel LiftLT's coding performance consistently
surpasses that of the much more complex 9/7-tap biorthogonal wavelet with
floating-point coefficients. More importantly, our transform's
block-based nature facilitates one-pass sequential block coding,
region-of-interest coding/decoding as well as parallel processing.