-showindicator
When no user interface is used to acquire images (-noui or -nouiwait), specifying -showindicator will allow the progress indicator to display itself when acquiring an image.
The progress indicator is usually implemented as a separate window with a bar or scale stating the progress of the acquisition, however the look and feel of the progress indicator is solely up to the driver itself. Below is an example of a typical progress indicator:
Only TWAIN compliant devices that implement the progress indicator according to the TWAIN specification are supported. Many devices implement progress indicators that cannot be turned off, and many devices may not have a progress indicator implemented, thus making -showindicator ineffective.
Default Setting:
If -showindicator is not specified, the progress indicator is not shown when acquiring without a user interface (-noui or -nouiwait)