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Posted 25 May 2004


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Motion detection using web cam

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9 Jun 20043 min read
Motion detection using webcam, by C#.

Sample Image - md01.jpg


This text tries to clear out the mystery of how to make motion detection using web cam with C#. My friend Walied want to capture video to his office by a web cam for 24 hrs, but the problem is that the space required on hard-disk is very extreme. So, he asked me to make a way to save disk space. Walied proposed to make a motion-detection circuit (IR, Ultra sonic) and connect it to the PC serial port and check for input every period of time. If there is any input then run the record program and start to capture video. But I replied that it’s a bad way because the thief will run away before the slow computer requests a web cam to start capturing video.

So my idea was to take a picture from a web cam every period of time (make it the current picture) and compare it with a previous picture and if we find a big difference between them we will save both pictures else will free memory from the old picture and make the new picture the current picture.

But there are two big problems:

  1. How to talk with your web cam and grab frame (picture) from it?
  2. How to compare the two pictures?


  1. There are two ways to talk to a web cam:
    1. Use DirectX's component called DirectShow (but unfortunately, DirectX doesn't provide DirectShow component for C#. NETMaster made an assembly to face this problem in his article DirectShow.NET). //Elgitaro: check this.
    2. Use a 3RDPARTY like cam server (you can find it in Laurent Kempé 's article Dynamic Webcam Image).
  2. There are also two ways to compare 2 pictures:
    1. By comparing each pixel's color for both pictures.
    2. Using filters to detect edges, then object recognition...

    I think method (a) will work faster because we are talking about a period of 3 m secs.


This is my algorithm:


First, grab image from web cam called Old. Second, grab another image from web cam after a while, called Cur. Compare Cur & Old by comparing each pixel color. If difference is greater than tested value (according to the quality of your web cam & light system you are using is 60 or 50 Hz), then save the two pictures. Finally, make the old picture the Cur picture. Back to second step (infinite loop).

Let's write some code:

  • Get the camserver.dll & ijl15.dll (copy both files to c:\windows\system32 and then write regsvr32 camserver.dll in Start->Run to register the COM component).
  • Make new Windows project, paste three PictureBoxes in your form, paste two Buttons and finally, paste a Timer control and set its enabled property to false.

Your form looks something like this:



This program will not work as fast as I need because of the time for IO operation. So I use another technique to make it fast, by capturing a video to a panel and then grabbing image from it. This makes the application work faster as I need. This application is called CatchItV, and the first one called CatchIt (please try both and send me your comments).


This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

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About the Author

Taha Elsayed
United States United States
Senior Development Manager, with 11 years of experience. Focused on design/developing/delivery B/OSS modules to satisfy customer/business requirements in accordance to TM Forum's TAM/SID framework. Excellent communication and interpersonal skills, flexibility, ability to adjust to new people and situations, strong problem solving skills and willing to work effectively and efficiently. Gained additional leadership skills such as: - High effective mentorship and coaching - Clearly communication and solutions sharing with my team - Decision making

Comments and Discussions

Questionhow to save video in this article Pin
Member 1267153127-Sep-16 6:58
MemberMember 1267153127-Sep-16 6:58 
Questionsaving in video form Pin
Member 126099014-Aug-16 23:15
MemberMember 126099014-Aug-16 23:15 
GeneralMy vote of 3 Pin
Игорь Жилин30-Nov-14 12:56
MemberИгорь Жилин30-Nov-14 12:56 
GeneralMy vote of 4 Pin
Member 1094452113-Jul-14 23:57
MemberMember 1094452113-Jul-14 23:57 
QuestionUrgent!!! Pin
Member 858515426-Feb-12 18:39
MemberMember 858515426-Feb-12 18:39 
GeneralTUNER Pin
nithinravi53526-Dec-10 22:55
Membernithinravi53526-Dec-10 22:55 
GeneralDear Mr. Taha Amin Pin
uvik30-Sep-10 11:33
Memberuvik30-Sep-10 11:33 
QuestionIn which assembly i found camserver.dll & ijl15.dll ? Pin
Saira137-Apr-10 17:28
MemberSaira137-Apr-10 17:28 
Questionmotion detection using web cam in C# Pin
Saira137-Apr-10 4:34
MemberSaira137-Apr-10 4:34 
Generalmotion detection code with MATLAB Pin
rasul631420-Mar-10 11:02
Memberrasul631420-Mar-10 11:02 
GeneralRe: motion detection code with MATLAB Pin
trzik292-May-11 23:36
Membertrzik292-May-11 23:36 
Generalhelp Me! Pin
brysamae26-Jan-10 20:02
Memberbrysamae26-Jan-10 20:02 
GeneralRe: help Me! Pin
uvik30-Sep-10 22:54
Memberuvik30-Sep-10 22:54 
GeneralDetect movement from left or from right Pin
ALEXNG8828-Dec-09 2:21
MemberALEXNG8828-Dec-09 2:21 
GeneralThanks Pin
Du Sijun15-Dec-09 2:02
MemberDu Sijun15-Dec-09 2:02 
GeneralI need a help! Pin
thurein0916-Jul-09 3:08
Memberthurein0916-Jul-09 3:08 
Questionneeds some advice for my FYP "Golf Swing Analysis Software" Pin
Oak Soe26-Jun-09 5:45
MemberOak Soe26-Jun-09 5:45 
QuestionRetrieving the COM class factory for component with CLSID {FDD4C8C1-69C9-11D3-9DC8-525400E38CF9} failed due to the following error: 80040154 Pin
alish06105-Apr-09 20:02
Memberalish06105-Apr-09 20:02 
QuestionHelp me Pin
findingbooks1-Apr-09 21:41
Memberfindingbooks1-Apr-09 21:41 
Generalnice article Pin
arunvikc21-Feb-09 21:51
Memberarunvikc21-Feb-09 21:51 
GeneralRetrieving the COM class factory for component with CLSID {D6BA1539-8473-497C-92C3-8ECF63DAC0F3} failed due to the following error: 80040154. Pin
Omsk28-Dec-08 23:39
MemberOmsk28-Dec-08 23:39 
QuestionRotating of WebCam Pin
Yena papa16-Sep-08 4:04
MemberYena papa16-Sep-08 4:04 
QuestionHow to get the Video Stream From CF Camera Pin
vison_xuan14-Apr-08 6:22
Membervison_xuan14-Apr-08 6:22 
Questionhow many percent changes in the video will consider motion? Pin
tansc25-Feb-08 21:46
Membertansc25-Feb-08 21:46 
QuestionHow to capture avi file? [modified] Pin
Hady CV18-Nov-07 3:46
MemberHady CV18-Nov-07 3:46 

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