The majority of IP cameras available today support a feature known as ‘Motion Detection’ or ‘Video Motion Detection’ (VMD). This is a very useful feature for security applications as it will detect when something has moved in a scene and can notify the user in a number of ways including email or activating external alarms or lights etc.
Sometimes though you might find that it triggers when there is very little movement or it triggers when other objects move in the scene such as traffic or plant-life outside a visible window or pets indoors.
Fortunately most IP cameras come with ways to help reduce the number of false alarms such as masking, multi-window detection or sensitivity settings.
What this guide will show is various ways we can configure motion detection in an Axis camera.
This guide will be suitable for all Axis IP camera models with the exception of the Axis 206.
HOWTO:
Step 1 - Accessing the Motion Detection Settings
Axis 207W Setup Pages (firmware version: 4.40)
From the menu on the left select the ‘Event Configuration’ option. This will expand a new set of menu options below:
From the menu select the ‘Motion Detection’ option to access the motion detection settings. You should see a page similar to the one shown below:
Axis 207W - Motion Detection Settings (firmware version: 4.40)
Step 2 - Setting Multi-Window Motion Detection
An Axis camera supports multi-window motion detection allowing you to set up motion detection events in specific areas of the overall image. This allows you to set up complex alarm management rules which can cover doorways, windows, valuable belongings etc. This is also more efficient and quicker than using the entire scene as your motion detection zone as the camera only needs to detect motion on the smaller area and not the full image. Note: if no windows are configured then the camera will not be able to use it’s motion detection features at all.
Select the ‘Add Window’ button at the top right hand side of the page to add a new motion detection window. The window will be added at a set position and size as shown below (up to 10 windows can be added at any one time):
Axis 207W - Example motion detection window (firmware version: 4.40)
This default window can be repositioned, resized and renamed.
By using the mouse you can move the window by dragging the title bar to your desired position on screen.
The window can be re-sized by using the mouse and dragging the window from the bottom left or right hand side until it matches your required window-size.
By re-sizing and re-positioning our window we will set it up over the door to cover the entrance to the room as shown below:
Axis 207W - Example motion detection window (firmware version: 4.40)
Futher settings can be applied to each individual window. To apply these first click on the title bar of the window to select it and you will see further settings on the right hand side of the page:
Tabs: At the top of the settings there is a small tab that reads ‘0′. This signifies that the default window we have placed on the page is window zero. When you place more windows on the screen (up to a maximum of 10) these will be numbered 0-9 respectively and each window has it’s own unique settings which can be accessed by selecting it’s numbered tab.
Include/Exclude: An include window is a standard window where motion will be detected. An exclude window is a mask which we will look at in step 3.
Name: Under the include/exclude options is a textbox which allows you to name your window. If you add a meaningful name to your windows it will make it easier later when using your windows to set up events. We are going to call ours ‘door entry’ as it will cover our door.
Object Size/History/Sensitivity: These settings adjust the sensitivity of the motion detection routines. We will discuss these in more detail in step 2.
View All Windows/View Selected Window: These are simply viewing controls which affect how the windows are displayed on the interface, ideal if you have a large number of windows configured and want to display the selected window only.
Our newly named window:
Axis 207W - Motion Detection Window with Custom Name (firmware version: 4.40)
Step 2 - Sensitivity Adjustment
The sensitivity of the detection routine can adjusted to suit if you feel that the camera registers too many triggers. This helps reduce the number of false alarms made by the camera.
There are three settings that can be adjusted: Object Size, History and Sensitivity.
Object Size: Detects object size relative to region size. If set to a high level will only detect very large objects in the window. If set to a low-level it will detect small objects as well as large.
History: This is the objects memory length. At a high history level, an object that appears in the region will trigger motion detection for a long time before it is considered a non-moving part of the image. At a low history level an object that appears in the region will trigger motion detection for only a very short period. It will then be considered a non-moving object in the image.
Sensitivity: Detects difference in luminance (or the perceived brightness of color from the image or the contrast difference between the object and the background). At it’s highest level ordinary colored objects on ordinary backgrounds will trigger a response. At it’s lowest level only very bright objects on a dark background will trigger motion detection.
At the bottom of these settings is a graph which gives a graphical representation of the motion detection status:
When the peaks go over the object size line (black horizontal line) they turn red a register a positive detection. This helps when adjusting your motion detection settings.
Step 3 - Masking
It is also possible to mask out unwanted areas of an image from motion detection calculations. This allows areas with constant movement such as an office fan, or trees moving in the wind through an open window etc. to not trigger any motion.
You set a masked window in the same way as our motion detection window above but instead of selecting ‘include’ (which creates a motion detection window) you select ‘exclude’ to select a mask window.
You can then position the mask over any active window and any movement within the masked area will be excluded from any motion detection calculations.
In our example we have masked the windowed area over the door so that people passing in the corridor won’t trigger our alarm but our alarm will trigger if the door is opened:
Finish
So by combining the use of multiple detection windows, masked areas and sensitivity adjustment you can effectively reduce the number of false alarms made by the camera.
If you have any questions, comments or feedback please leave them below.
