This file must contain wavelet filter coefficients stored in the file format described below. The standard file extension is .wff (wavelet filter file).
Each .wff file consists of a header part (the H-lines in the table below), and a data part (the D-lines in the table below).
| line number | line name | contents |
| 1 | H1 | Dataplore ® wavelet filter file |
| 2 | H2 | wavelet type: <type> |
| 3 | H3 | size of lowpass analysis: <size-la> |
| 4 | H4 | size of highpass analysis: <size-ha> |
| 5 | H5 | size of lowpass synthesis: <size-ls> |
| 6 | H6 | size of highpass synthesis: <size-hs> |
| 7 | D1 | <double> |
| ... | ... | ... |
| m | D<n> | <double> |
Line H2 specifies the wavelet type. <type> must be either
"orthogonal'' or "biorthogonal''. Lines H3 to H6 contain the number
of filter coefficients of the corresponding filter. Lines D1 to D<n>
contain the filter coefficients. Each line carries one coefficient. If
the wavelet is orthogonal, <type>=orthogonal, lines D1 to D
<n> contain the coefficients of the lowpass and highpass filter in that
order. Hence <n> is equal to <size-la>+<size-ha>. If
the wavelet is biorthogonal, <type>=biorthogonal, lines D1 to
D<n> contain the coefficients of the lowpass analysis, highpass
analysis, lowpass synthesis and highpass synthesis filters in that
order. Hence <n> is equal to <size-la>+
<size-ha>+<size-ls>+<size-hs>. The filters must be
normalized so that the sum of the coefficients of the lowpass analysis
filter and the sum of the coefficients of the lowpass synthesis filter
are 
.