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.
ADR 0007	A project is spent once exported; reopening starts fresh. Reverses an earlier decision.