Mobile phones with cameras and Internet access can scan QR codes and read the contents or be directed to additional information via the Internet. Most laptops and many desktop computers also have webcams and Internet access so why are there no QR code scanners for these?
Hunting around on the Internet I found one French company that required registration and motivation before they allow you to download anything. After registering I hade to wait a day to receive an email requesting I send them motivation before they would allow me to download anything related to QR code scanning on desktop computers. I found this very strange as the scanners for mobile devices were easy to anonymously download.
The making of a desktop QR code scanner/reader
Having a creative engineering spirit I set out to make a desktop QR code reader for my desktop for myself. Having just the weekend to do it I set out using my favourite Microsoft Visual Studio environment. First task: detect and get access to the webcam. After trying using the VIA driver API which was extremely slow and unreliable, I opted for addressing the windows avicap32.dll directly. Now I had a smooth video stream and it worked on several different laptops and desktops with different webcams without any problems.
Next came the tricky part: Capture video frames, convert to high contrast image and detect if a QR code is present. For the need for speed in development I opted to use the clipboard as temporary capture buffer. Converting the images to as high a contrast as possible using the source image luminance and histogram data. The video stream is based on the 32 bit API of Microsoft, so for now Windows 7 is a 'no go', but I'll be working on this soon.
Building on and extending an open source QR code library from 2007 by "Thoughtworks" made it possible to have the image data passed to the QR recognition routines for processing in no time. This library saved me days of work.
Upon a positive identification of a QR symbol, the content is read and the text is diplayed in the box under the video stream. The system will also try to execute the target application based on the result of the contents of the code. Example: If it detects a 'http://' it will endevour to launch a browser using the result as the URL.
A Windows based QR code scanner application for use on laptops and desktops.
.net 3.5 runtime
For those technical and for programmers also wanting to work with QR code software, A great open source library to start with can be found on The Code Project
One thing to note: This was a lighting speed mini project (to get me through the weekend). It is not built to be industrial and bulletproof. All I wanted was a simple scanner for my desktop to test the QR codes I generate. So if you use it and have any suggestions or comments for extentions or improvements, then please let us know.
Free QR code scanner download
You can download the zipped instalation of the Desktop QR Scanner and install it on your computer. It will create a folder called "Desktop QR Scanner" in your program files folder. The program is called DesktopQRScanner.exe. Start it up and you should be ready to start scanning QR codes from your laptop or desktop computer as if it were a mobile phone.