motion detection?

Posted on 2001-09-13
Last Modified: 2010-05-18
any algorithm for analysing pictures and reporting if any motion detected? any ideas where to start searching on this subject?

Question by:zastava101
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions

Expert Comment

ID: 6481318
As a start, you can subtract an image from a later one. Only moving objects and noise will appear in the difference. The edges are highlighted for the objects that move, in the direction of motion. You can use this to measure the motion.

Cross correlation will let you pick similar obejcts out between two images.

You should learn about fourier transforms to understand some of the details.


Jaehne Digital image processing 1991 Springer
Pratt Digital image processing 1991 Wiley
Gonzalez, Woods Digital image processing 1992 Adison Wesley
and Lim

To experiment you could start with subrtaction, use an offset to stop numbers going negative.

One way of looking at motion is that you are looking at tited objects in the 3D space of images. (stationary objects form pillars in this space, the same in every plane)

Good motion detection is critical to Mpeg4 encoding, so it is a very current field.


Expert Comment

ID: 6481344
the logitech quickcam (a very inexpensive webcam) has some algorithms for motion detection.  Check for more info about webcams and the SDK for quickcam programming (there is a way to link it to delphi. Search also here for webcam programming and Delphi).

Hope this help.
Manuel Lopez (lopem)
LVL 11

Expert Comment

ID: 6481492
OpenCV from Intel is a Open Source project for image algorithms. It is in C, but accessing the DLLs from Delphi should be possible.
Search Intels website for "OpenCV". There is a mailinglist at
Join by sending an empty message to
Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

LVL 12

Accepted Solution

Lee_Nover earned 100 total points
ID: 6482044
hi .. I have the code made in Delphi
it uses FastLib components (free)
here it is

add fastdib, fastblend, FConvert, FastFX to uses clause

  oldDIB, newDIB, diffDIB: TFastDIB;
  lastBMP: TBitmap;

// I just took the code out and put it in this dummy procedure
procedure DetectMotion;
var C, w, h, x, y, t: Integer;
    // load the new bitmap from anywhere

     if lastBMP.Handle = 0 then exit;
        oldDib.MakeCopy(newDib, true);

        // load the source .. then copy it grayscale to newDIB

        FConvert.ConvertTo(diffDIB, 16);
        FastFX.Grayscale(diffDIB, newDIB);

        diffDIB.MakeCopy(oldDIB, true);
        FastFX.Grayscale(diffDIB, oldDIB);
        FConvert.ConvertTo(diffDIB, 8);

        FastBlend.DifBlend(diffDIB, oldDIB, newDIB);


        for x:=0 to w do
            for y:=0 to h do
                Inc(C, diffDIB.GetPixelB(y, x));


     if (c = 0) then
     else// number of pixels * number of bits
        t:=Trunc((C * 100) / ((h+1) * (w+1) * 8));
     // we get the average lightness in t

... now just check your ratio (change percent)

this works great for me :)
about 0-1% cpu usage on (pIII 550) 100 msec check intervals

Expert Comment

ID: 6484040
LVL 14

Expert Comment

ID: 6485618
Lee_Nover, welcome to Experts Exchange.

I think it was not appropriate to make your post an answer because of the following:
* As I can see, your code does only detect whether motion was present, but not WHAT has moved. In many application it's important to detect WHAT has moved.
* Only post something as answer if you are "300% certain" that this is the one and only answer to the
question, and no other exuert has answered it already (maybe as comment).

Comments can be accepted as answer by the person which asked the initial question, so that you don't
have to be afraid of posting comments. If your comment is the one which answers the question best, you'll
get rewarded even though you did not post an answer. Comments do not lock the question for others, that's
why most experts choose to comment only so that other experts have a chance of seeing the question and post their opinions.

For more information, please read 
LVL 12

Expert Comment

ID: 6486712
well looking at the question (any algorithm for analysing pictures and reporting if any motion detected) ...

in the future i will post comments not answers

I just hope it does what zastava101 wanted

Expert Comment

ID: 6489572

Expert Comment

ID: 6499221

Expert Comment

ID: 6872423
ADMINISTRATION WILL BE CONTACTING YOU SHORTLY.  Moderators Computer101 or Netminder will return to finalize these if still open in seven days.  Please post closing recommendations before that time.

Question(s) below appears to have been abandoned. Your options are:
1. Accept a Comment As Answer (use the button next to the Expert's name).
2. Close the question if the information was not useful to you. You must tell the participants why you wish to do this, and allow for Expert response.
3. Ask Community Support to help split points between participating experts, or just comment here with details and we'll respond with the process.
4. Delete the question. Again, please comment to advise the other participants why you wish to do this.

For special handling needs, please post a zero point question in the link below and include the question QID/link(s) that it regards.
Please click the Help Desk link on the left for Member Guidelines, Member Agreement and the Question/Answer process.

Please click you Member Profile to view your question history and keep them all current with updates as the collaboration effort continues, to track all your open and locked questions at this site.  If you are an EE Pro user, use the Power Search option to find them.

To view your open questions, please click the following link(s) and keep them all current with updates.

To view your locked questions, please click the following link(s) and evaluate the proposed answer.

------------>  EXPERTS:  Please leave any comments regarding your closing recommendations if this item remains inactive another seven (7) days.  Also, if you are interested in the cleanup effort, please click this link
Thank you everyone.
Moderator @ Experts Exchange

P.S.  For any year 2000 questions, special attention is needed to ensure the first correct response is awarded, since they are not in the comment date order, but rather in Member ID order.

Expert Comment

ID: 7071432
Zero response, finalized.

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Delphi: making a BW image transparent 10 135
DBCtrlGrid, Delphi, Scroll 7 34
Firemonkey Queue list 1 50
QuickReport, Delphi, Shape 12 44
Creating an auto free TStringList The TStringList is a basic and frequently used object in Delphi. On many occasions, you may want to create a temporary list, process some items in the list and be done with the list. In such cases, you have to…
Introduction I have seen many questions in this Delphi topic area where queries in threads are needed or suggested. I know bumped into a similar need. This article will address some of the concepts when dealing with a multithreaded delphi database…
With Secure Portal Encryption, the recipient is sent a link to their email address directing them to the email laundry delivery page. From there, the recipient will be required to enter a user name and password to enter the page. Once the recipient …
How to Install VMware Tools in Red Hat Enterprise Linux 6.4 (RHEL 6.4) Step-by-Step Tutorial

737 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question