Is Your Axis Camera Crying Wolf? How to Tame Oversensitive Motion Detection
Axis Communications cameras are professional-grade surveillance tools, renowned for their power and flexibility. However, with that power comes the need for proper configuration. If your system is generating a constant stream of alerts from minor events like moving shadows, rain, or small animals, it's not just an annoyance—it's a critical issue known as 'alarm fatigue', where real events risk being ignored.
The key to solving this lies in correctly configuring the Axis Video Motion Detection (VMD) application. This guide is for system administrators and installers looking to reduce false alarms and create a more efficient and reliable surveillance system.
## Common Causes of False Alarms in Professional CCTV
Before adjusting settings, it's important to understand what's likely triggering the system:
- Environmental Changes: Moving shadows as the sun goes behind clouds, headlights from passing cars, rain, snow, or fog.
- Vegetation and Animals: Trees, bushes, or flags blowing in the wind. Small animals, birds, or even insects close to the lens.
- Lighting Changes: Automatic lights turning on or off, or the transition from day to night mode (IR cut filter).
- Poor Initial Configuration: The default, out-of-the-box VMD settings are often too sensitive for a real-world outdoor environment.
## A Professional's Guide to Configuring Axis VMD
Access your camera’s web interface by typing its IP address into a browser. Navigate to Settings > Apps > Axis Video Motion Detection. Here, you can create and edit VMD profiles.
### 1. Define Precise Include and Exclude Windows
This is the most crucial step. Don't just use the entire scene as your detection area.
- Include Windows: Create one or more polygonal windows that tightly cover only the areas of interest. For example, draw a window that covers a doorway, a garden gate, or a specific section of a car park. Be as precise as possible.
- Exclude Windows: If an 'include' window has to contain a source of nuisance alarms (like a busy road in the background or a large, swaying bush), draw an 'exclude' window over that specific part. The system will ignore all motion within the excluded area.
### 2. Fine-Tune Object Size and Sensitivity
These two sliders work together to filter out insignificant motion.
- Object Size: This setting allows you to define the minimum size of an object, as a percentage of the total screen area, that can trigger an alarm. Increase this value to ignore small objects like birds, cats, or falling leaves. Draw the box to be slightly smaller than the smallest object you do want to detect (e.g., a person in the distance).
- Sensitivity: This slider determines how much an object's pixels need to change to be considered motion. In a stable, indoor environment, you can use high sensitivity. For a busy outdoor scene, you will need to decrease the sensitivity significantly to avoid alerts from things like shadows and rain.
Pro Tip: Make small, incremental changes. Adjust one slider, observe the results for a day, and then adjust again if needed.
### 3. Utilise Advanced Filters
Axis VMD includes powerful filters designed specifically to combat common false alarm sources.
- Swaying Objects Filter: This is extremely effective for outdoor scenes. It analyses objects that move but then return to their original position within a set time (e.g., a tree branch). You can set the 'time to return' (e.g., 5-10 seconds) to ignore this type of movement.
- Short-Lived Objects Filter: This filter ignores objects that appear and disappear very quickly, such as car headlights or lightning flashes. Set the filter to a few seconds to discard these transient events.
### 4. Set Up Multiple Profiles
You don't have to rely on a single configuration. You can create different VMD profiles for different times of the day. For example, you could have a less sensitive 'Day' profile and a more sensitive 'Night' profile that activates when your IR illuminators turn on. You can then use the camera's event system to schedule when each profile is active.
By methodically applying these professional configuration techniques, you can drastically reduce false alarms and turn your Axis camera into a highly accurate and reliable detection tool.