Back to how recognition worksWhat's new in OMR

PDF & photo scanning: what's new.

Opuscan's scanning, powered by optical music recognition (OMR), keeps getting better. This page records updates to PDF and photo import, newest first.

28 September·Improved·

A new model version that reads uncommon time signatures and lines without a clef

Our scanning model has been updated, with a focus on time signatures, clefs and multi-bar rests.

  • More time signatures are read as printed. The model now knows 29 time signatures plus common and cut time. New this month: 6/4, 7/4, 8/4, 9/4, 10/8, 11/8, 13/8, 14/8, 15/8, 9/16, 11/16, 13/16, 15/16 and 17/16, common in folk, jazz and contemporary music. Before, they were replaced with a familiar one (10/8 came out as 12/8, 8/4 as 5/4), the bars no longer added up, and notes were removed to make them fit. See every notation scanning supports.
  • Multi-bar rests keep their real length. In band and orchestra parts, a number above a long rest tells you how many bars to count. That number is now misread far less often. Before, a "10" could become 100, and your part ended up with dozens of extra empty bars.
  • Lines without a clef stay at the right pitch. Many parts, especially jazz charts and older editions, print the clef only on the first line of the page. The model used to guess a clef for the other lines, and a wrong guess moved every note on the line up or down. Those lines now keep the clef of the line before.
  • Fewer things that aren't on the page. A small "3" over a triplet is no longer read as a fingering, no octave line (8va) is added where none is printed, and a stave that is silent for a whole line is no longer filled with drum notes.
  • More of your notes make it into the score. When a bar is read with more beats than its time signature allows, some notes have to be left out so the bar adds up. Since rhythms and time signatures are now read more accurately, this happens much less often: on the imports we tested, about 70% fewer notes went missing.

Also in September

32 smaller changes
7 August·Improved·

A new model version with support for implicit tuplets

A new version of our in-house model now powers every PDF and photo import, with a focus on how tuplets are printed on the page.

  • Implicit tuplets are now supported. Engravers usually print the small "3" or "6" over the first triplet or sextuplet of a passage only, and leave the groups that follow unmarked — the player is expected to carry the pattern on. Those unmarked groups are implicit tuplets: played as tuplets, with nothing printed to say so. They are very common in 19th-century editions, studies and variations. Scanning now reconstructs them from the rhythm of the bar, instead of dropping notes to make the bar fit its time signature.
  • Fewer tuplets invented out of thin air. The model used to mark ordinary beamed groups as triplets even when no number was printed above them, and those numbers showed up in your score. It now writes a tuplet only where one is actually printed on the page.

Also in August

19 smaller changes
29 July·Improved·

A new model version focused on scanned music accuracy

A new version of our in-house model now powers every PDF and photo import, with 22% to 51% fewer errors on our scanned sheet music benchmarks. The gains are biggest on harder pages - older engravings and uneven print.

24 July·Improved·

A new model version focused on notation fixes

An improved version of Flat's in-house model now powers every PDF and photo import, in particular:

  • Multi-voice passages with shared rests and invisible rests are now supported.
  • Barlines and repeat endings (voltas) are now placed correctly within measures.
  • Beams are recognised more reliably.
  • Time signatures drawn across several staves, as on orchestral scores, are now recognised.
  • Fixed some chord symbols that were exported to MusicXML with a non-standard chord type.
21 July·New·

Opuscan for Windows

Opuscan - our standalone scan-to-score app - is now available on Windows, alongside macOS, iPhone, iPad, and Android. Scan a page or open a PDF, and get an editable, playable score you can export to MusicXML and MIDI - no Flat account required.

15 July·New·

Opuscan for iPhone and iPad

Opuscan - our standalone scan-to-score app - is now on the App Store for iPhone and iPad, joining the macOS and Android apps. Photograph a page or open a PDF, and get an editable, playable score you can export to MusicXML and MIDI - no Flat account required.

10 July·New·

Dedicated Opuscan apps for macOS and Android

Opuscan - our standalone scan-to-score app - now has dedicated apps for macOS and Android. Built on the same in-house OMR engine as Flat, it lets anyone turn a PDF or photo of sheet music into an editable, playable score and export it to MusicXML and MIDI - no Flat account required. It's made for people who just want the scanning technology to feed their favourite music software, from notation editors (MuseScore, Dorico, Sibelius, Finale) to DAWs (GarageBand, Logic Pro, Ableton Live). Get it on the Mac App Store or Google Play.

Also in July

11 smaller changes
23 June·Improved·

Sharper page analysis for complex layouts

We've improved how scanning reads the layout of a page. Imports of PDFs and photos now produce cleaner, more accurate scores, especially on complex layouts:

  • Dense pages now split correctly. Pages with many short systems stacked on top of each other are no longer merged together - each system is detected separately.
  • Better on orchestral and large-ensemble scores. Multi-staff instruments such as piano and organ, and large scores with many staves, are recognised more reliably.
  • Wide, landscape, and booklet layouts. Landscape pages no longer clip the left edge (which could cut off clefs), and multi-page and booklet scans are handled correctly.
  • Fewer stray detections. Spurious elements near page footers and margins are no longer picked up as music.
15 June·Improved·

A more accurate model

Every PDF and photo import is now processed by Flat's own in-house model. This release is a major new version focused on transcription accuracy: musical correctness (the notes, rhythms, ties, and accidentals that determine whether a score is right) improves across every test set, with the largest gains in:

  • Dynamics: +39%
  • Fermatas, articulations, ties, accidentals: +30 to 37%
  • Note durations: +22%
  • Slurs, dotted notes, rests, staff and voice assignment: +14 to 20%

Text, dynamics, and layout placement are also more precise: lyrics, chord names, and dynamics attach more reliably to the correct notes, including on complex layouts such as piano grand staves and parts with clef changes.

1 June·New·

Our own AI model starts rolling out

We're rolling out Flat's own AI model for PDF and photo import, designed and trained in-house to replace the third-party engine used at launch. Owning the technology end to end lets us push accuracy further, broaden what we recognise, ship improvements far faster, and align results with Flat's own notation format so imports fit naturally into the rest of the product. This first release already reads much more of your music:

Broader notation coverage. Newly recognised:

  • Chord symbols, properly encoded with their musical meaning as editable chords, not just plain text
  • Measure repeats and rhythm slashes
  • Tempo and metronome markings (with BPM)

Lyrics and text in more languages. Lyrics, rehearsal marks, and other text are recognised in Latin-script languages by default, plus Japanese, Korean, and Chinese.

Truer to the original layout. Imports now follow the source score's layout much more closely, matching the number of measures per line, systems per page, and overall structure. This makes a real difference on large, complex scores such as orchestral works and multi-staff instruments like piano. It also supports more page formats, including landscape pages that weren't supported before.

Also in June

8 smaller changes