Miscellaneous

FAQ

1. Demonstration Programs

1.1. twexplore.py displays a grey image instead of the image scanned.

2. General

2.1 Why does my window go into the background after a Scan

1. Demonstration Programs

1.1. twexplore.py displays a grey image instead of the image scanned.

This problem occurs when the image scanned is very large. If you use the defaults to scan an A4 page on my HP scanner, you get a 14meg image. This image does not get displayed by the test program, but it can be viewed using paint-brush.

You can reduce the size of the data scanned by modifying the size of the data selected, the pixel type or the resolution. Frame selection is available as a button on the 'Acquire' screen. Pixel type and resolution are modified via attributes (i.e. select ICAP_PIXELTYPE or ICAP_XRESOLUTION with double-click and modify.

2. General

2.1. Why does my window go into the background after a Scan.

When an image is scanned, the scanner user interface is displayed (or at least takes some control of the message queue). This is a separate process from your application. When the scan is complete, the scanner user interface is closed. Windows finds a window to activate in another process.

There are some windows messages passed around e.g. WM_ACTIVATE, which may provide a facility to move the application window to the front. Alternatively, call the scanner from a modal dialog.

Miscellaneous