Some Tips on Scanning Lecture Notes

The new semester just began, and I’ve decided (again) to try to digitize my notes from the courses I’ve taken. I’ve tried my hand at the task several times over the years, and I thought it would be nice to share my 2 cents’ worth of tips on how to do it properly.

Things You’ll Need

• A scanner with an automatic document feeder (ADF). The ADF is really important; without it, scanning is a nightmare. If you don’t have one, get one (they’re really cheap). Your office probably has one with duplex scanning, which is even better.
• A good scanning software that supports creating PDFs. I use XSane; the GUI isn’t great, but it does the job. I’ve also tried Simple Scan, which didn’t work properly for me, and the default HP software for Windows (I can’t describe bigger bloatware).
• pdftk – A great program for manipulating PDFs.

The Scanning Process

There are three relevant scanning options, in my opinion, for handwritten notes:

• 300 DPI grayscale. This results in around 550 KB for each page of notes. Quality is great, but sometimes you can see the writing on the other side of the page in a slight gray.
• 600 DPI black and white. Quality is a bit lower than grayscale, but the size is about half, just 200 KB per page. It takes longer to scan, but an ADF usually means it’s not an issue.
• 300 DPI BW. This will again reduce the size, but this time at a noticeable loss in quality. I recommend this only if file size is your greatest concern.

In order to make the choice a bit less vague, here are some example scanned pages: 300 Gray, 300 BW and 600 BW. The notes are written using a rollerball pen (Pilot V-Ball Grip). Here is another comparison, this time using a ballpoint (Fisher Space Pen). As you can see, the quality difference is more pronounced with the ballpoint. Hence, if you want your scans to be smaller and keep the quality, use a rollerball and 600 DPI. If you use a ballpoint, pay the price and go for 300 DPI grayscale. Also, stay away from blue pens; they are less readable in grayscale and might be unreadable altogether in BW (I’ve tried to make some simple image manipulations to improve scanning blue-ink to black and white, for which I have some improvements that hopefully I’ll release sometime).

I’ll also use plain white paper intended for printers. I find it of higher quality (and cheaper) than ruled paper, and it results in better scans.

Page Reordering

If you’ve a duplex scanner, this tip isn’t for you. For the rest of us, the most convenient method to scan paper I found is to make one scan for the odd pages and then take the pile, flip it, and scan the even pages (back pages) from back to front (reverse order). Afterwards, use pdftk to join them:

pdftk A=odd.pdf B=complexity-even.pdf shuffle A Bend-1 output final.pdf

That’s my 2 cents on scanning lecture notes. If you’ve got other great tips, comment and share them.