Add a soprano recorder tab converter as a Linux AppImage.

The app turns a lead line into Baroque fingering tabs with rhythm kept, ships Twinkle and Ode to Joy, and reads photos locally with oemer when the bundled Python is present.

Co-authored-by: catpersonisme <catpersonisme@gmail.com>

scripts/run_oemer.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env python3
+"""Read one sheet-music image with oemer and print the MusicXML path.
+
+oemer asks ONNX Runtime for CUDA first. This wrapper forces the CPU provider
+so the AppImage does not need a GPU.
+"""
+
+from __future__ import annotations
+
+import os
+import sys
+import traceback
+
+
+def force_cpu() -> None:
+    import onnxruntime as rt
+
+    original = rt.InferenceSession
+
+    def cpu_session(model, providers=None, **kwargs):  # type: ignore[no-untyped-def]
+        kwargs.pop("providers", None)
+        return original(model, providers=["CPUExecutionProvider"], **kwargs)
+
+    rt.InferenceSession = cpu_session  # type: ignore[method-assign]
+
+
+def prepare_png(src: str, dest: str) -> None:
+    from PIL import Image, ImageOps
+
+    with Image.open(src) as image:
+        rgb = ImageOps.exif_transpose(image).convert("RGB")
+        if min(rgb.size) < 80:
+            raise ValueError("This image is too small to read as sheet music.")
+        rgb.thumbnail((2200, 2200))
+        rgb.save(dest, "PNG")
+
+
+def recognize(png: str, out_dir: str) -> str:
+    from argparse import Namespace
+
+    from oemer.ete import clear_data, extract
+
+    def once(deskew: bool) -> str:
+        clear_data()
+        args = Namespace(
+            img_path=png,
+            output_path=out_dir,
+            use_tf=False,
+            save_cache=False,
+            without_deskew=not deskew,
+        )
+        return extract(args)
+
+    try:
+        return once(True)
+    except (Exception, SystemExit):
+        traceback.print_exc()
+        return once(False)
+
+
+def main() -> int:
+    if len(sys.argv) != 3:
+        print("usage: run_oemer.py IMAGE OUT_DIR", file=sys.stderr)
+        return 2
+    src, out_dir = sys.argv[1], sys.argv[2]
+    os.makedirs(out_dir, exist_ok=True)
+    png = os.path.join(out_dir, "page.png")
+    try:
+        prepare_png(src, png)
+        force_cpu()
+        musicxml = recognize(png, out_dir)
+    except Exception as exc:  # noqa: BLE001 — surface a single readable failure
+        print(f"{exc.__class__.__name__}: {exc}", file=sys.stderr)
+        traceback.print_exc()
+        return 1
+    if not musicxml or not os.path.isfile(musicxml):
+        print("oemer did not write MusicXML", file=sys.stderr)
+        return 1
+    print(f"MUSICXML={musicxml}")
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())