Each Haar pass is one flat pywt.downcoef call over a raveled strip instead of
pywt.dwt(..., axis=1)[0], and the plane is walked in strips so no full-plane
float64 intermediate exists. Exact only while the last axis is even, so
_approximation raises on an odd width rather than returning wrong bits, and
TestRaveledHaarPass pins both that raise and the downcoef/dwt equivalence a
pywt upgrade could take away.
Drops the block constructor knob: the fold chains are written for 4, nothing
ever passed another value, and a knob that silently decodes wrong is worse
than no knob.
Peak RSS 111 MB to 21 MB on a 4.3 MP image; the decoder itself 0.011s to
0.007s, which is only 0.4% of identify() now that it is under 2% of the run.
Output bits and detector verdicts over 200 sampled data/ images, two
synthesized carriers and eight degenerate shapes are byte-identical to the
pre-vectorization decoder.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Output stays bit-identical: decoder bits and detector verdicts recorded over
200 sampled data/ images plus two synthesized carriers before and after, and
the record is byte-identical.
Measured on a 1536x2816 image -- decoder 0.280s to 0.016s, warm identify()
1.757s to 1.365s with both arms timed in one process.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
