Esa Kataja
974c91a727
Project state plus PDF in, finished slice images out. Slices are cut as polygons rather than row ranges, so a stepped cut yields a slice with a transparent notch instead of one that covers its neighbour. Masking paints white, which the ink-to-alpha step turns into full transparency — the same outcome the spec asks for, one step earlier. Scale normalises every slice to the median staff height before fitting the song to 1920px, so a rescanned page sits at the same note size as its neighbours. The cap only ever shrinks: a song narrower than 1920 stays narrower. Alpha quantisation rounds to 16 values spanning 0-255 inclusive. Flooring, as first written, capped full ink at 240 and left every note 6% transparent — caught by decoding an exported slice rather than by reading the code. Ketun joululaulu exports 24 slices at a uniform 1489px, under the cap and correctly not upscaled from its 200 DPI source; Feliz Navidad 20; Elaman nalka 18. Closes #21 Closes #22 Closes #23 Closes #24 Closes #25 Closes #27
noteman-slicer
Turns a score PDF into the ordered slice images noteman consumes, plus the navigation markers that sit on them.
A slice is one system — one full line of music across all voices, typically 4–12 bars with lyrics intact. noteman displays them as a continuous vertical scroll, so the slicer's job is to cut a printed page into systems, clean them up enough to read on a tablet, and tag them with the score's navigation symbols.
Status: design only. No code yet. The design is settled; see below.
How it works
Open a PDF, and the tool proposes cuts between systems, a skew correction, and a content rectangle. You correct all of it — source quality varies too much for unattended processing, so detection is an accelerator that nothing depends on being right. You mark the header and footer regions discarded, set black and white points until the paper disappears and the notes go solid, place the rehearsal letters and jump markers, fill in the title block, and export.
Out comes one zip: the slices in order, their markers, the original PDF, and the song metadata. That bundle is the only channel to noteman — there's no API between the two tools.
Erasing previous-owner pencil marks, chord letters and breath marks stays in GIMP. That's the irreducible manual part, and GIMP with a stylus is already good at it.
Installation
Not yet installable. When it is:
uv tool install --editable .
That puts a noteman-slicer command on PATH which runs from any directory — no venv to
activate. Dependencies (PyMuPDF, PySide6, OpenCV, numpy) are all wheels; nothing
needs a system package.
Documentation
| CONTEXT.md | Glossary. What a slice, cut, discard, bundle and song scale actually mean here. Start here. |
| docs/spec.md | The specification: pipeline, geometry model, detection, editor, bundle format, and what noteman has to change. |
Deferred work is tracked as issues and milestones on the Gitea repo, not in this tree.
Decisions that were expensive to reach, each with the evidence behind it:
| ADR 0001 | The slicer owns all image processing; the bundle is the only channel to noteman. |
| ADR 0002 | Raster only in release 1 — measured SVG slice sizes and what they showed. |
| ADR 0003 | Lossless WebP beats every lossy option and every alternative format here. |
| ADR 0004 | No unattended mode: detection suggests, a human confirms. |
| ADR 0005 | PyMuPDF for all PDF access, accepting AGPL. |
| ADR 0006 | Systems are found by vertical brackets; row-darkness gaps get it wrong. |