Cool Windows 7 application that controls monitor backlight using ordinary webcam

Code 7 Contest BLUntrl

If you have a webcam attached to your desktop computer then there’s a good chance it’s either sitting around gathering dust or taking hourly pictures of your uneventful window. One way or another, getting any value out of it when you’re not video chatting would be a nice bonus. Now with Windows 7’s Sensors API and a neat application, not only could it be productive but your eyes might thank you for it.

One of the more interesting entries into the Windows 7 “Code 7 Contest” is an application called “BLUntrl”. This conceptually simple but highly practical application lets you do on your desktop what newer model laptops also do – automatic backlight control.

However since desktops don’t have ambient light sensors built-in, this application turns your webcam into one through the “magic of software” and then hooks into the native Windows 7 Sensors API and the monitor configuration APIs to adjust the backlight of all your attached monitors for optimal brightness, according to ambient lighting conditions.

Anyone who use a computer near a window can easily testify how much lighting conditions can change and affect the readability of monitors. Also, night owls like myself will also know just how glaring a brightened monitor can be in a dark room. In both cases, adjusting the brightness can help.

In the accompanying video submitted by the developer he also suggests building in a feature that can detect motion using the webcams which perhaps could be used to intuitively suspend the monitors if the user leaves the desk.

[flv:code7_BLUntrl.flv 500 375]

The Code 7 Contest ends October 10. Good luck “sonic”.

28 insightful thoughts

  1. Cool idea. But the monitor has to support backlight adjustement via software, I guess, and that doesn’t seem very common.

  2. My NEC has a built-in ambient light sensor. Never really used it until now. Having it on in a dark or badly lit room is indeed slightly better on the eyes.

  3. I have found something looking remarkably like this at what I think is the developer’s website:

    There aren’t any public links yet though, so if I’m not supposed to have posted this (I found it by guessing the filename, found the directory via google), please delete the comment.

  4. Pretty cool idea.. Since were talking about monitor and backlight I thought id throw Fl.ux into the mix.. Changes colour temps based on time of day etc.. Hated this at first but after tweaking for type of lighting and setting proper location bearing with it for a few days.. Now I can’t live with out it.. Check it out here..

  5. @Martin: Thanks for the tool. My monitor, a Samsung SyncMaster 275T, works with it!

    @AT: Excellent snooping 🙂 That looks like it’s his app.

  6. Finally some useful app using the Sense-sors API. Room temperature and stuff like that was useless. Location and use of webcams (monitoring light) and microphones (monitoring sounds) makes it seem at least of some use.

  7. Hmmm. I can change the brightness via software using the windows mobility center, but the app doesn’t work.. do I need to have something installed, since sensors in control panel doesn’t show as anything installed? Seems like this app requires some sort of driver.

  8. Wow, I really like this idea. I tried the app linked above and it wakes up my camera and seems to make some slight adjustements to brightness but I hope the Code 7 Contest version puts a nicer UI on it 🙂

  9. “If you have a webcam attached to your desktop computer then there’s a good chance it’s sitting around gathering dust and taking hourly pictures of your uneventful video chatting.”
    I fixed that for you.
    I’d like to see this technology implemented into a 2x4cm power efficient device/sensor you can place on any monitor without having to constantly run a webcam.

  10. It’d be nice if you could use some of the gestures in Windows 7 and Microsoft Surface through my old webcam which is gathering dust on my desk

  11. I tried using the zip file posted above and it didn’t do anything. I have a Dell Studio 1537.. It’s not even a year old. I’m sure it should support the stuff that this file requires. Please let me know what to do to get it to work.

  12. oh ya.. i should be able to support programmable changes because when i use my linux OS, it has a brightness applet which allows me to control brightness using a slider.

  13. can we use webcam for motion detection.
    please suggest me how to configure or use webcam with application program

  14. Great. I can’t believe no one thought of this before though. The problem with this concrete app is that it requires your webcam to be not auto-adjusting. Otherwise mean brightness levels always get adjusted right back by the camera and, in consequence, also the brightness of the screen.

    I’m subscribing to this thread in case there are any valuable follow-ups.

  15. The code7contest site seems to be down.. is there a link directly to the author / app somewhere?

  16. I guess the project is dead. Maybe someone can reverse engineer it for linux before he patents it.

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