ImageFile imageFile = null;
CommonDialogClass cdc = new WIA.CommonDialogClass();

try
{
    imageFile = cdc.ShowAcquireImage(WIA.WiaDeviceType.ScannerDeviceType,
                                    WIA.WiaImageIntent.TextIntent,
                                    WIA.WiaImageBias.MaximizeQuality,
                                    "{00000000-0000-0000-0000-000000000000}",
                                    true,
                                    true,
                                    false);
}
catch (System.Runtime.InteropServices.COMException)
{
    imageFile = null;
}