Module wavelet 

Separable multi-level 3D wavelet transforms by lifting.

• CDF 9/7 (f64 lifting, the JPEG 2000 irreversible filter): the lossy path. Float, but plain IEEE +/* in a fixed order with no fused ops, so the CPU decoder is deterministic.
• LeGall 5/3 (integer lifting, the JPEG 2000 reversible filter): the lossless path, exact on i32.

Both use whole-sample symmetric extension and work on any length ≥ 1 (odd lengths keep the extra sample in the low band). The pyramid is dyadic on the LL region; at each level every axis whose current length is ≥ MIN_LEN is split, so a 64×128×128 block gets 4 levels on its short axis and 5 on the others (anisotropic bands where axes stop early). Arrays are always handled as 3D, with leading unit axes for 1D/2D input.

Structs

Band

A subband: level level (0 = finest), orientation mask (bit a set = highpass along axis a; mask == 0 is the final LL), half-open region.

Pyramid

The dyadic pyramid for a shape.

Constants

MAX_LEVELS

Level cap for 2D/3D arrays.

MAX_LEVELS_1D

Level cap for 1D signals (and the size of the basis-norm table).

MIN_LEN

An axis is split at a level only while its LL length is at least this.

Functions

as3

Pad an n-D shape (n ≤ 3) to 3D with leading unit axes.

forward_53

Forward multi-level integer 5/3 in place.

forward_97

Forward multi-level CDF 9/7 in place.

fwd53

One level of forward integer 5/3 (reversible) on x.

fwd97

One level of forward CDF 9/7 on x (in place: low half first).

inv53

Inverse of fwd53.

inv97

Inverse of fwd97.

inverse_53

Inverse multi-level integer 5/3 in place.

inverse_97

Inverse multi-level CDF 9/7 in place.

norms_97

1D synthesis-basis norms (lo[k], hi[k]) after k splits (lo[0] = 1).