Windows Virtual Scanner

The project is ported from twain-samples.

Pre-requisites

• Visual Studio 2017 or above
• Qt 5.12.11 msvc2017

Environment Setup

• Add system variable QTDIR: msvc2017 (x86) or msvc2017_64 (x64)
• If you have multiple Qt Kit directories in system path, move the target kit directory ahead of others. Otherwise, when running windeployqt.exe to deploy a Qt project, it will fail to copy the correct dll files.

How to Build

1. Start Visual Studio as administrator.
2. Open TWAIN-Samples\Twain_DS_sample01\visual_studio\TWAINDS_VS2017.sln.
3. Build the project. The relevant files will be copied to C:\Windows\twain_32\sample2\.

How to Test

• Open the virtual scanner in Dynamic Web TWAIN online demo.

  

• Open the scanner in twacker.

  

How to Debug

1. Run twacker.

2. In Visual Studio, set a breakpoint in DS_Entry() and then go to Debug > Attach to Process to find the twacker process.

   

3. Click the Attach button and then select the virtual scanner to trigger debugging.

   

How to Load Custom Image Set

1. Create a source.json file which contains the folder of custom image set. For example:

   {
       "folder": "C:/Users/admin/Pictures/barcode"
   }

   Copy the JSON file to C:\Windows\twain_32\sample2.

2. In the folder of custom image set, create a info.json file which contains the index of current selected file and max image count for ADF:

   {
       "index": 0,
       "maxcount": 10
   }

3. Use twacker to scan the custom images one by one. The index will be auto-updated if your folder have Write permission.

   

Blog

How to Build Windows Virtual Scanner and Feed Custom Images