Submitted by drew on

 

Just to document this for next time. For reference, my books are 8 x 10.75 inches and other dimension below work for this. For approximately 100 pages, It takes me about 45 minutes to scan, an hour to crop and rotate, and 30 minutes to organize and generate the PDF.

Scanning

Myscanner is an all-in-one type of printer with a 8.5 x 11 scanning bed (Epson Workforce 3640). When I replaced my previous printer, I considered getting one with a 11x17 scanning bed, but alas, did not. So anyway...

Scan at 200dpi using the "Text and images" setting.

Set the output format to TIFF. I would have used PNG, but that's not available on my scanner. Perhaps next time I will use the JPEG setting and see if that affects the final quality (perhaps not since we are reducing and compressing quite at bit by the end).

Image Processing

Using IrfanView for each image...

  • Rotate to the correct orientation (press R)
  • Do fine rotation if needed, usually in the range of .3 to .6 degrees, if the scans are fairly straight (CTRL-U).
  • Crop (select the region to keep and press CTRL-Y)

Batch process all images in the folder. Open one of them in IrfanView and press B. Use these settings...

  • Reduce size by 50%. This results in an image approx 750 by 1050 pixels.
  • Convert to JPEG using the highest quality setting.
  • Add all images to the batch.
  • Select the output folder.
  • Run the batch.

Organize and Generate the PDF

Using LibreOffice Impress...

  • Change the page size to 7.75 x 5.25 with 0 margins. This should allow drag'n'drop the images into Impress without having to resize all of them.
  • Each Impress slide is a full page spread (two facing images).
  • For each spread, you could link to the image by CTRL-SHIFT-dragging the file into Impress, but Impress seems to have some issues with linked images. So embedding seems to be the way to go.
  • Rename slides via right click or press F2. These slide names appear in the final PDF as bookmarks.
  • Export to PDF using my exporter script with "Export to PDF for Web" option on the File menu

Using PDF-XChange Editor (free version)...

  • Organize the bookmark hierarchy (i.e. into sections).

 

Converting version control repositories from Bazaar to Git (bzr to git)

Submitted by drew on

Bazaar is great on Windows. Several years later, git's tools for Windows still.... (ahem) are lacking or too commercial. However, official development on it has ended and git is so much more popular now. So I think the time has come to convert all my beloved bzr repositories to git.

First we need note some prerequisites:

Adding a hardware clock to Raspberry Pi (DS3231)

Submitted by drew on

The popular clock module is uses the DS1307 real time clock chip, which is not very precise. For just a few dollars more, you can get a module with a much more precise DS3231 RTC chip. The one I got was SunFounder's module from Amazon for $9 (free shipping for Prime). It plugs right onto the Raspberry Pi's 40 pin header and doesn't even interfere with the plastic case I have. I have a Model B, but this module should also work on Model A and Model B+. The instructions refer to DS1307, but the chips use the same I2C commands, so it also works for DS3231.

How to run a PiPresents show when you don't have a Raspberry Pi

Submitted by drew on

PiPresents is some pretty cool software that will run a PowerPoint-like presentation. But with lots more flexibility. It was originally written for the Raspberry Pi.

However.... perhaps someone else has your Pi. Perhaps you don't even have one. It is possible to run a PiPresents show on  your good ol' desktop computer (Windows, Linux, or Mac). Here's how.