Snac Help

While the usage of Snac is quite straightforward, the setup can be kind of tricky and this help concentrates on that.


Setting up Snac for your scanner involves quite a few steps, but nothing really difficult. You will have to use the terminal to some extent (or download Snac and use the links provided in the helpfile).

Before you start you need to have SANE installed. If you haven't installed it yet, you could download a binary package of the SANE backend from Mattias Ellert's homepage.

If you don't know if you have installed SANE, you can continue with the setup and you will find out.

  • Start by locating the scanimage program that's included with the SANE backend. Go to the terminal and type which scanimage.

    The command will give you the full path to the scanimage program. Copy that and paste into the corresponding field in the Snac preferences.

    If the command doesn't give any output, you most likely don't have SANE installed. Install it and restart...

  • The next step is to run scanimage and ask for the device-specific parameters. The easiest way to do this is to go back to the terminal and execute the command scanimage --help.

    This will print many usage options on the screen. The ones that are important to us start below the text "Options specific to device...". Find the options that control the scan mode (like grayscale or color), bit depth, resolution and the geometry of the scan. Enter the information found here in the corresponding field in the Snac preferences.

    For my Artec scanner, the scan mode is controlled with --mode Lineart|Grayscale|Color. I therefore add --mode into the "Option to set modes" field and Lineart, Grayscale, Color into the "Available modes" field.

    For the geometry of the scan, Snac assumes that the scanner accepts the top left corner and the size of the area to be scanned. If your scanner defines the area in a different way, please contact me at the adress in the page header and I will try to solve it for you.

  • If you want to automatically open the scanned image in an external application, enter the full path in the corresponding field or browse for it by pressing "Browse" and open the wanted application.

That should conclude the setup and you're ready to do some scanning...


After Snac is properly setup, the actual usage is simple. Note however that the canceling of a scan sometimes freezes the scanner.

  • Start with making a preview by pressing the preview button (or command-P). The preview is scanned in the selected mode, with a resolution of 50 dpi (or the closest approximation) and using the full scannable area.

    When the preview is done, it will show up in the preview panel.

  • Select the area you want to scan by dragging in the picture and press the Scan button (command-S).

  • When the scan is complete, a save dialog will show up and when the picture is saved, it will open in the selected helper application if that option was checked.