Discrete coefficients filter banks and applications in image coding
Discrete coefficient filter banks reduce the computational complexity for subband image coding systems. A new time domain formulation is proposed for the design of near-perfect reconstruction filter banks with discrete coefficients. It can be shown that the proposed design method yields an l/sup 2/ optimal solution which is considered to be practical in image coding applications. In addition, special emphasis is placed in designing filter banks with nonnegative scaling functions that smoothly decay to zero at block edges in order to reduce basis related artifacts. As a result, the reconstructed image does not suffer from blocking and ringing artifacts at medium bit rate (25:1 compression at 0.32 bit per pixel.).