Motion Detection - Video saved without motion detected


#1

Hi, I can’t see my problem here, so I’ll just ask. I’m (for now) running unlicensed with 1-2 cams. I have a problem with the motion sensor. Some times video is being saved without any movement on it. The motion indicator up left shows nothing. It seems there is no reason for this, so I guess it’s time to ask here.

Best regards Remi


#2

Hi Remi!
As usual it can be a number of things so let´s start :slight_smile:
-how often is a false recording saved? one every hour, once a day, …
-have the system been running without problem for a long time and this problem just started?
-did you change anything in the configuration of the motion detection?
-it can be something in front of the camera lens, but it is so quick that you cannot see it on the video depending on how many FPS is used for the recording.
-it can be a problem in the camera that generate electrical noise that is interpreted by the software as a movement.
-something in the computer.
-…

-The easiest way to sort this out is to put a black paper in front of the camera. Still problem or not?

-Henrik


#3

I see I have a bit weak bank of data here… :stuck_out_tongue:
I THINK it happens around once a day and it’s been happening for a while, don’t think it came with any changes. I just installed a temporary parallel camera, so I’ll se if this goes for both of them. The older cheap camera I’ve been using and seeing this problem with is running stable at 9-10fps. Can it be that the motion indicator indicate only between two images, at less than 1/10th of a second, not visible at the video?

Two other things… Not sure if it’s possible, but is there any settings that makes motion less sensitive for snow in the air?
Is it possible in multi cam view to arrange the images over/under, instead of side-by-side? Two 16/9 cams would be much more visible over/under in half of a 16/10 display.


#4

In the config of motion detection of the camera you can set the Frame Interval (default 200 ms) that is the time between two frames that is used for the motion detection algorithm.

Snow, rain drops, … are not so easy to things to compensate for since they usually change in time, size, intensity. You have Motion Sensibility and Threshold to work with. Only way is to test. Put the View in Motion view where you can see in real time what triggers the motion detection. Be careful not to filter away whats really interesting.

Good suggestion for the video layout. I think so too. I put that on the to-do-list.


#5

Yeah, thought so, motion is motion, and a flake of snow will not only move but change shape for the camera as the angle changes so I didn’t think it would be possible. One thing though, I think the range of sensitivity for motion is too narrow. It seems that it makes little difference when changing sensitivity from VeryHigh to VeryLow. I’ve only tested with the cheap 640x480 camera so it may have something to do with low pixel count. It stayed too sensitive in both ends (actually could not say witch setting was more tolerant) so I would wish for a bigger difference between the steps or just more steps. If I have the time the next time it snows I’ll give you some feedback on how the two parallel cameras with different resolution (and waay different over all quality) react to same or different sensitivity settings.

Btw. Running one cheap “SRICAM” or something, IP with motors, $25ish on ebay and a fixed 1920x1080 with Sony IMX322. The last one seems to be really good, especially in low light.

The video arrangement I guess is just… “just” some work, but I think it would be worth it, well, for us users at least :smiley:

Over all I’m really happy with the software. In time I might buy a license, I might want more cams. I will recommend it for some family that I think should have some cameras watching the animals at their farm. Maybe I’ll even offer them installation :slight_smile:


#6

If you are wiling to spend two or three zeros more on the software you can probably find something with a more intelligent detection system with pattern recognition, correlation, … Going all in just to remove snow flakes :wink:

Mostly I am running the web client or mobile client in my systems, but as you say it cannot be that difficult ;).

Thanks for the positive words. For the farm animal they definitely need a surveillance system to keep track of what they are doing.
Good luck!
Henrik


#7

For my use it was never an issue spending any money. Though, if I find use for more cams I would actually consider buying a license, 'cos I think this is by far the best free software I’ve found. And when you take the time helping out and advising even for freebees, well I think that’s worth buying, I like it when the right people get a bit for their work.

I would say that this software might not be big-money-developed, but would do the job for most private and smaller companies. As for the farm, if it comes to that, they will obviously be needing a proper licensed product :stuck_out_tongue:


#8

For what its worth, I’ve had similar problems of empty pictures taken in response to detected motion with WebCam-XP. Though a different product, I believe the detection methods are similar. As near as I could tell, watching the live video feed along with noting the time stamps of photos triggered by motion, the false trigger issue was simply caused by the changing daylight, for example when a cloud dims the sun over a short time span, or when the cloud passes. This is likely because the motion detection algorithm breaks the live image into a grid of small squares, and responds to changes in light within a given number of squares. Refining the software based analysis to distinguish between such changes to better favor actual motion is not an easy task, especially using just a visible light camera.

I suspect if the programmers become aware of this behavior and give it some thought, they will eventually be able to improve the detection process. But just realize that in ANY alarm system, there is always a gray area between detecting what you want to detect, and ignoring what you don’t care about. That said, it is usually better to err on the side of responding too much, than to respond to too little too late.


#9

Speaking of “Motion View”, I wish there was a way to record that type of view. Because when I have it in that view and sitting in front of the computer, well, of course there is no motion to record and capture. But when I am away, I always gets false recordings and it would be nice to “see” what Netcam saw and why it triggered the recording.

And I too agree with the sensitivity setting from VeryHigh to VeryLow. I would expect as I change the range, it would go from recording just about every single second of video at the VeryHigh end, to rarely recording any vide on the other end. But that doesn’t happen (I have mine set to VeryLow), so I think the range is too limiting also.

And I too would consider purchasing a license (I’m currently only testing with a single IP cam) and getting more cameras, IF I could get the recordings to be meaningful to me. I get way too many false recordings to make it convenient for me. I use it only when I know someone/something would have triggered the recording (like what time the UPS guy showed up), but I would rather use it for situations like “Huh, I have two recordings today, I wonder who was here!?”. Unfortunately I haven’t yet found the proper configuration settings to get me there.


#10

Hi guys!
I like your discussion and you are certainly not alone in this. If is a difficult area and interests many so here is my input in this. If it helps or not … ;).

Motion detection is a tricky business and is in focus for research and development since many years. As a lot of high tech stuff today used in everyday systems and applications it emanates from the military. Search the Internet and you will find a lot of very interesting articles about this and the development of mathematical algorithms trying to find the target in different ways. Today we use only a small part of this in the free or licensed softwares, but still the purpose is the same; to keep track of the mail man, check on our pets, children, unwanted guests in the backyard, …

In NCS there are a couple of different algorithms to chose from, but the basics are the two parameters Motion Sensibility (not sensitivity) and Threshold. Here you can find more about these two parameters Difference between sensibility and threshold

-Sensibility is a parameter connected to how the motion algorithm should respond to a fast or slow movement of the object.
-Threshold is a parameter connected to how the motion algorithm should react to how much of the sensor area in the camera that the object cover.

Since this is about motion detection these two parameters closely interacts to trigger the system to start a recording. It is important to know that in these simplified systems the motion detection system do not know if what generates the trigger for a recording is the arriving mail man or a cloud in front of the the sun that generates a moving shadow on the ground. Of cause there are systems that can distinguish between these two things. More sophisticated software and hardware with a different price tag, but this also put more demands of the user. There are many articles about this and here is two of them that are quite enlightening:

-Motion detection and objects tracking algorithm implementation

-Motion Detection Algorithms
https://www.codeproject.com/Articles/10248/Motion-Detection-Algorithms

So, what to do?
Finding the target in an outside environment is difficult if you want no “false alarms”. If you know what you are looking for, like a person, I suggest that a person pass in front of the camera on the desired distance and then you change the Threshold and Sensibility until you get the best result. Most likely it is the Threshold that you find easy to adjust. Remember, that the person will cover different amount of area on the camera sensor depending on the distance from the camera so the Threshold will also determine at what distance the moving person will be detected.

I would set the Sensibility to Normal since that parameter is more of a fine tuning. Maybe a very slowly moving Turtle is not of interest to record, but it still covers a large area on the sensor. Then it can be of interest to decrease the Sensibility.

If it is difficult to find out what is actually triggering the system I would set it to continuous recording and on motion detection for a day. Then it is possible to see everything and also the moment when the system trigger. If it is outside it can be a shadow, leaves on a tree or what ever is in the camera field of view.

I also like to use the View -> Motion detection since that assist me a lot to see what trigger the system. I have been testing different settings and have not found a way to also record that view. I certainly agree with you on this so I am sending this to our developers if thay can do their magic and involve this overlay also in the recorded file.

During night time it is usually ever more difficult since there are a lot of annoying bugs, maybe snow flakes, rain drops, … that reflects the light from the IR LEDs back into the camera and generates a lot of false recordings. To solve this one solution is to mount an external IR source a bit from the camera and turn off The IR LEDs in the camera.

Good luck guys and you know where to find me ;).
-Henrik


#11

My cheap camera triggers Motion when it’s reacting to changes in light. Light sensitivity changes in steps so the picture turns brighter or darker in fairly big steps. I am aware of this and it’s easy to spot on the saved films. I don’t think this camera can be stopped from having this behavior, so this problem I hope to solve with using another camera. I’m testing with a much better camera and have not seen Motion trigged due to changes in light, but I think the “good” camera still have had a few “ghost” recordings. I’m not 100% sure though, but I have seen Motion trigged on the old camera, not caused by this known problem with changes in the light.

Well well, I bought the wrong camera with only wired connection, now I’m waiting for a similar camera with WiFi, that’s the camera I’ll be putting effort in. So if anyone here lives in Norway and need a good wired IP-camera let me know :slight_smile:


#12