I need to scan LOTS of music to put it into a MusicPad
(
http://www.freehandsystems.com). I have a Canon LIDE 30 which has been
doing good work in the past. For this project (started last week) I haven't
been able to get good enough quality. The suggested scan resolution is 75
dpi. The problem is the staff lines in the music -- they're very fine. My
scans have been giving me staff lines of varying thickness making it hard to
read.
A different scanner is not going to help this problem. CIS is not this
problem, that is out of context here.
This problem is that 75 dpi is simply insufficient resolution to resolve the
very thin lines well. At 75 dpi, each line is only about 1 pixel wide (the
space between lines may be only about 4 pixels, but 4 pixels is enough that
the spaces resolve well enough). You simply need more pixels to resolve
this fine detail into a bitmap image. Higher resolution.
Unfortunately, I understand a larger image becomes unusably large for this
application. You need the 75 dpi image size. But otherwise, if you could
scan it larger, the quality improves greatly, with the resolved detail
becoming sufficient to resolve these fine lines easily. For example,
scanning at 600 dpi line art mode (all scanners should have three modes:
color, grayscale and line art, but the line art mode is sometimes named B&W
Document mode or a similar name), then printing a copy on a good printer
should have fabulous quality. Fantastic detail at 600 dpi, the printed copy
virtually indistinguishable from the original (this is the test of your
scanner). But 75 dpi simply cant do that well at all (grayscale is your
best chance at 75 dpi). So this issue is just that your application
requires very low resolution, really insufficient for a bitmap image of that
small size to be able to resolve the finest detail (those fine lines).
The site above has a FAQ that says:
Digital music files in pdf, jpg and other popular graphics formats can be
directly imported through the FreeHand software into the MusicPad Pro.
Printed music can be scanned into your computer and then imported to the
MusicPad Pro. Better looking results may be obtained by using OMR software
such as Smart Score combined with your scanned music.
Their last sentence seems the key for best results.
If you had the "source file" for this printed music (that being the file of
data for symbols of musical notation, which was used to print the musical
notation in the first place, which is NOT a scanned bitmap image of the
page), then that source file could be printed to PDF (same as printing to
paper), and the PDF copy would retain perfect quality, every bit as good
as the printed paper page, and you could use that in Music Pad (they say).
It would not be a 75 dpi bitmap trying to show a line only one pixel wide.
It would not be a bitmap image at all.
It is the same as scanning text characters. Print real text characters to
PDF from a word processor, and you get perfect quality. Print those text
characters on paper, and scan the paper at 75 dpi, and you get far less
quality. And those text characters are relatively large and thick compared
to the fine lines you are scanning.
When you scan the printed music page into a bitmap image, and if the detail
width is on the order of only one pixel dimension (at 75 dpi, an 11 page is
only 825 pixels tall. The lines are only about 1 pixel width.), then there
is a serious alignment problem of the line and the scanner pixels which are
to detect it. Some of the lines may be aligned well enough with the sensing
pixels by random chance, but not all of them can be aligned. Any slight
skew or misalignment will be tragic to quality, since the detail is only on
the order of size of one sensing pixel. That is insufficient resolution to
resolve the line well.
But if the line were wider, or if the resolution were higher (same effect),
say so that the line were maybe 4 pixels width at say 300 dpi, or even 2
pixels wide at say 150 dpi, then alignment is not much issue, and all lines
come out well resolved. Unfortunatly, that larger image is too large for
your purpose. Resampling the large image smaller will give the same
insufficient size for this tiny detail.
But if you scanned (at higher resolution than 75 dpi) this music page into
music software designed to optically recognize the printed symbols from
scanned images, and convert the music back to "original source", that is, to
again be data representing the music notation, but which is no longer a bit
map image, then you could "print" that new source data to PDF and retain
perfect quality. Same as printing the original page again. Then it is all
vector drawn postscript lines, without any concept of pixels then. The lines
will be perfect reproductions.
So (for this small image size) the best scanning solution would seem to be
scanning into the music recognition software, and also then using PDF
software to print that source directly to PDF. This recognition is of
course also going to require much more work and time than just one simple
scan, and more software and process steps. Some manual intervention and
data correction may likely be necessary, same as when using OCR software.
Before you commit too far too quick, you surely want to discuss this topic
with the MusicPad support people, who should know a little about actual
experience. I dont know about that topic, but I do know that a 75 dpi
bitmap is insufficient resolution to reproduce your fine lines well.
