As an arranger I might have my prejudices, but I cannot believe that
scanning music will give you any sort of good music.  My experience
(e.g., with MIDI files sent to me to arrange) is that it is much
cheaper and _faster_ to write the score _manually_ again, almost
always only by _listening_ to it.

It might cost some time for writing it down but one gets intimate
with the music, which is a precondition to the following phase(s) of
actually "making music": Finding the tempo and its slight variations;
thinking about duplicating notes to create a more interesting
arrangement (e.g. on instruments without crescendo possibilities) etc.

So, in the end, the "tedious" manual writing job will save you much
more time ... and it's more fun, too!  :-)

Harald M. Müller
Grafing b. München
Germany