WaveletFilterCoefficients

WaveletFilterCoefficients[wave, filt] gives the filter coefficients for the symbolic wavelet wave of type filt.

Examples

Get lowpass filter coefficients for Daubechies wavelet:

WaveletFilterCoefficients[DaubechiesWavelet[4], "PrimalLowpass"]

Get highpass filter coefficients:

WaveletFilterCoefficients[HaarWavelet[], "PrimalHighpass"]

All filter types:

WaveletFilterCoefficients[DaubechiesWavelet[2], #] & /@ 
  {"PrimalLowpass", "PrimalHighpass", "DualLowpass", "DualHighpass"}

Please visit the official Wolfram Language Reference for more details.