University of Minnesota
School of Mathematics
School of Mathematics         Superposition of the cAMP wave (dark blue) and the cell streams.  
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Scanning Images and Documents

The deparment has a few ways of getting images.

Working with Images and PDFs

Images can be viewed with web browsers, the desktop file browser, and applications like eog or gthumb. The Gnu Image Manipulation Program (Gimp) is a photo editor available on Linux (Mac and Windows) you can use to crop and edit the scans.

PDFs can be viewed with evince, okular, Adobe Reader and xpdf. PDFs can be annotated with OpenOffice (limited) and Xournal.

Gscan2PDF for Multiple Page Scans

Despite the name, gscan2pdf can scan and output a few formats like PDF and DjVu. The portability of PDF is a plus, but DjVu can create smaller files for longer (100+ page) documents.

Documents can be scanned in color or grayscale, and while scanning can be done at high resolution you can save at a lower DPI like 150. Lower resolution PDFs should be snappier to read on portable electronics.

Guides to Running (X)Sane

SimpleScan and gscan2pdf are easier to use than sane or xsane, but you might want access to all the controls that (x)sane offers.

But xsane is probably too cumbersome compared to SimpleScan or gscan2pdf.

Scanning Images from the Command Line

A command line scanning program is available, see the man page for more details. 

$ scanimage --format tiff --mode Color > foo.tiff; eog foo.tiff

ImageMagick is a suite of command line tools for working with images. It can resize, rotate, crop and perform many of the operations that desktop photo editing software can do.

Troubleshooting Problems with ScanImage

If scanimage can't detect the scanner, try listing the permissions of the /dev/scanner* device and the usb entry it points to. To access the scanner, an account needs read/write access to the usb device. When Fedora 8 comes up the scanner is owned by root:lp, and when someone logs into the desktop the ownership is changed to user:lp. 

$ ls -l /dev/scanner-2-6  /dev/bus/usb/002/003
crw-rw---- 1 jdoe  lp   189, 130 2008-07-25 17:46 /dev/bus/usb/002/003
lrwxrwxrwx 1 root  root       15 2008-07-25 17:24 /dev/scanner-2-6 -> bus/usb/002/003
$ scanimage -L
device `epson:libusb:002:003' is a Epson GT-9300 flatbed scanner

Scanning Images with xsane

Keep in mind that quotas do apply for saving in your home directory so plan ahead before scanning a large or resolute image. It is possible also to save the image in /var/tmp. We recommend that if you are going to save in the /var/tmp directory, that you make a subdirectory to avoid conflicts with other users.
  1. Put the scan object on the scan bed.
  2. Start the scanning software 
    	$ cd ~
	$ xsane
  3. Accept the license if you want to use xsane.
  4. Four windows should open: Main, Histogram, Standard Options and Preview.

    Main
    Standard Options
    Histogram

    Preview
  5. Acquire a preview image. Click the "Acquire preview" button in the preview window. The scanner head will whir back and forth for less than a minute.
  6. Change the color mode. The default color mode is binary (aka black or white), but most people will want scans in either greyscale or color. Change the color model pull down in the Main window to select a color model besides binary.
  7. Select the region to scan in detail. Click and drag a rectangular region in the scan preview. Whatever you want to scan, it can be enclosed in a rectangular box. To tell the software about what the region is, click in the lower left corner, hold the mouse button down and drag to the upper right corner. Lift up on the mouse button.
  8. Click the "Scan" button in the main xsane window. The scanner head will whir back and forth. A window title "Viewer" will open with the scanned region.
  9. Save the image. In the "Viewer" window, select the file menu and click on the "Save Image" menu entry. If the image is text, xsane can also to convert it to text using optical character recognition (OCR).