"Correction" menu

As any other system based on computer recognition, PDFtoMusic is not infallible, and can make some mistakes, more or less impiortant depending on the quality of the document. You can interevene on the recognition result and apply amendments. These changes can be saved so that they are preserved when loading the document again.
PDFtoMusic offers two ways of saving these amendments.

In a general way, when using PDFtoMusic, always start by listening to the result through the "Performance > Play" menu option. If you hear any mistake, this mistake will probably be also present in the exported file. So it's highly recommended to fix it with the available tools, the "Correction" menu being one of them.

Instrument

For each staff found in the document, PDFtoMusic shows the related instrument. You can change this instrument as well as its volume, panning position, octave shift and semitone shift.

Through the semitone shift you can specify that an instrument in the score is a transposing instrument. For instance, a staff written for a clarinet is usually notated as a Bb transposing instrument (its semitone offset is -1) and an alto Sax as a Eb transposing instrument (its semitone offset is -9).

If the instrument is human voice, you can specify the language that Virtual Singer will use for singing the lyrics.

A check box activates globally the "surround" effect. This effect increases the panning separation of the miscellaneous instruments, for all the documents.

Staves and systems

When a line is full on page, music notation makes the whole set of staves restart at the next line. Each group of staves that are played together from left to right on page is called a system. There can be several systems on each page.

In order to save space, staves that don't play across a system are frequently not displayed in this system.

This can lead to tricky situations, where it becomes difficult to know which staves are part of the next system, and which staves aren't. For instance, if an instrument doesn't play in a system and is hidden starts to play at the next system, while another instrument stops playing, the number of staves in the two systems can be the same, while the staves aren't. In this case, only the staff name, its clef, or other indicators enable to understand the score structure.

PDFtoMusic includes specific algorithms that "follow" staff lines from a system to another. The "Staves and Systems" mode lets you change the way staff lines are connected together.
A description is provided here.

Areas

In this mode, you can define excluding or including areas.
These areas apply to character or line objects

- If at least one inclusion area is present on the page, all objects located outside any inclusion area are ignored

- Any object located in an exclusion area is ignored

This can be useful, for instance, if a group of characters is not well managed and troubles the recognition.
To add an area, click and drag.
To delete an area, right-click it then select "Delete" in the contextual menu
In the same menu, you can define what page range the area applies to.
Areas are saved along with the amendments made to the document. The "Edit > Delete all changes" menu option therefore also deletes all areas.

Fonts

A PDF document includes graphic objects (frames, lines, etc) as well as characters extracted from a font. Those characters can be either letters and digits, or music symbols.

PDFtoMusic has some manual font recognition settings that can help correct mistakes, which are described here.