Improving recognition of poor images
If your score is not playing well, one of these adjustments can often  fix the problem.
Error correction – this is an auto-correction feature that can spot mistakes in a score or or recognition errors.  In most music it works well, but in some music where there are false relations (notes played together on the same degree of the scale but with a different accidentals) Error correction may try to ‘correct’ these.  If this happens, turn the setting off.
Sampling/PDF process quality (PDF scores only) this allows you to alter how the music is processed.  Essentially this setting determines how densely the image is sampled.  Some scores translate better at a lower or a higher setting and it is worth trying different settings for best results.  For poor quality scores it is sometimes possible to find a ‘sweet spot’ where the music sounds best.  For dense scores containing many staves results may be better at the + end of the scale.
Image (iOS only) - this control can be used to compensate when an image or parts of it are very faint, or very black.  The dark end of the scale(left) makes the image darker, the right lighter.
PlayScore 2 automatically adjusts to compensate for a wide range of image exposure, even when there are shadows.  But in extreme cases this control can be helpful.
faint scores - scores produced by certain early music editors can have staff lines that are very faint compared to other objects.  Other types of score have stems and lines so thin that render faint in the PDF.  For faint scores generally try moving the slider left towards the dark end.
dark scores - where a score has an over-exposed look with thick lines and symbols merging into one another, try moving the slider to the right.