Convert PNG to MIDI

A scanned score or notation screenshot must be converted when a DAW, notation editor, keyboard, or hardware sequencer accepts .mid files but cannot use image files. The process works only when the PNG contains recognizable staff notation or another defined note grid; an ordinary image has no musical events to extract.

What PNG stores

PNG (Portable Network Graphics) is a lossless raster-image format used for screenshots, scanned sheet music, web graphics, and notation-page exports. Browsers, image editors such as GIMP and Adobe Photoshop, and notation programs such as MuseScore and Sibelius can create or open PNG files.

A PNG contains pixels, not pitches, durations, tempo, instruments, or controller data. Printed notation must first pass through optical music recognition (OMR), which detects staves, symbols, measures, and note relationships.

What MIDI stores

A Standard MIDI File, normally .mid or .midi, stores timed performance and control events: note numbers, note-on and note-off timing, velocities, tempo changes, program changes, and controller messages when present. It does not contain recorded audio, so playback depends on the receiving synthesizer, soundfont, plugin, DAW, or keyboard.

MIDI is compact and editable: notes can be transposed, quantized, reassigned to instruments, or corrected in MuseScore, REAPER, Ableton Live, Logic Pro, Cubase, and similar software. It does not preserve page layout, staff appearance, lyrics placement, or most engraving information from the source score.

Convert printed notation with OMR

For clean printed sheet music, use Audiveris as the free desktop OMR application, then use MuseScore to inspect the result and export MIDI. Audiveris produces MusicXML, which retains notation structure better than MIDI during correction.

1. Prepare the image before recognition. Scan paper scores at about 300 dpi or higher, crop borders, straighten skewed pages, and use an image with sharp black staff lines and noteheads. PNG resolution is determined by pixel dimensions; its embedded dpi value alone does not improve recognition.
2. In Audiveris, open the PNG with File → Open, then run Book → Transcribe.
3. Check the detected staves, clefs, key and time signatures, barlines, accidentals, ties, voices, and measure counts. Correct recognition errors before export where possible.
4. Use Book → Export Book to save MusicXML, typically as score.musicxml or compressed score.mxl.
5. Open that file in MuseScore through File → Open. Correct pitches, rhythmic values, rests, tuplets, repeats, and playback settings.
6. Select File → Export, choose MIDI, and save score.mid.

Commercial alternatives include SmartScore, ScanScore, and PhotoScore & NotateMe. They can recognize scanned notation and export MIDI or MusicXML, depending on edition and workflow. For a web-based option, Soundslice's score-scanning service can be useful for supported printed-score uploads; confirm its current export options and privacy terms before uploading unpublished or copyrighted material.

Images that need a different workflow

OMR is intended for staff notation. A piano-roll screenshot can sometimes be reconstructed only with a purpose-built image-analysis tool or manual editing: the pitch lanes, beat grid, tempo, note colors, and quantization must be known. Exporting the original project or MIDI from the source DAW is more accurate than interpreting a screenshot.

A waveform, spectrogram, album cover, photograph, or arbitrary drawing cannot be objectively converted to MIDI. Audio-to-MIDI software can estimate notes from an audio recording, but that is a different conversion and does not use PNG pixels as musical notation.

Accuracy and compatibility limits

Clean engraved music converts substantially better than handwriting, low-resolution screenshots, skewed scans, tablature, dense orchestral systems, lyrics-heavy pages, or scores with annotations over the notes. Common OMR errors include ledger-line pitches, dotted values, tuplets, accidentals, ties, repeat endings, and independent voices.

Inspect and audition the exported MIDI before performance or production use. If a hardware sequencer rejects the file, it may require a particular Standard MIDI File type, often Type 0 rather than a multitrack Type 1 file. Open the MIDI in a DAW or MIDI utility, merge tracks if required, and re-export in the format specified by the device manual.