Best Practices for Drawing Tripwires

Camera Placement

• Ideally, the camera view should enable the software to view and track people for 1-2 seconds before and after they cross over the tripwire.
• Make sure that there are no items blocking the camera’s view of the people entering. It is important to note that harsh sunlight and bright glare could cause problems. Mount the camera in the center of the doorway. If there is a double-door entry, the center of the camera’s field of view should align to match the center of the two doors.

                                

 

Tripwire Settings

How do I get to Tripwire Settings?

1. Visit https://app.prism.com
2. Refer to the left side bar and click “Settings”
3. Inside the “Settings” page click the subcategory “Cameras” button. This button is found under the “Admin” title.

                                     

 

4. When inside the “Cameras” page, locate the desired camera for a tripwire and click on it.     

5. After clicking on the desired camera for a tripwire, click the “Advanced Analytics” button on the far right of the screen.

6. Two options should appear after the click. Choose the button that says “Draw Tripwires” by clicking on it.

       

7. After clicking “Draw Tripwires” you will see the camera’s view. Click anywhere on the screen to begin drawing tripwire. Note: once tripwire has been drawn the Tripwire settings will appear.   

 

How do I use Tripwire Settings?

1. Enter a name to label the tripwire.
2. Select data labels to view the tripwire data on the page- “Sites” then under “Analytics”.

        

3. Once tripwire has been drawn on the camera’s image, the tripwire’s settings provide the option to count people crossing the tripwire in the selected direction(s). If chosen, the first option (1.) will count the people coming in both directions. The second (2.) and the third option (3.) will count correspondingly to the selected directions. 

         

4. Maximum duration is the tool used to set the limit of time in which a person needs to cross a tripwire in order to be counted. If a person exceeds the chosen amount of time, then they will not be counted.

        

 

How do I draw Tripwire?

1. To draw tripwire simply click the camera’s view on the screen and create the desired shape. When finished double-click the last point on the screen.

1. To add double tripwire click the double arrow button in the settings.
2. The finished double tripwire product should appear like image #2.
3. The points can also be moved around after creating the tripwire in any desired shape.

 

Tripwire Tips

Tip #1

• Our application gives you the ability to draw up to three different tripwires with different shapes and different distances from the entrance.
• Each of the three tripwires can serve as a trial as you are able to test them all at the same time and choose which is most accurate in counting.

* Recommended: Once you find a tripwire that provides you the most accurate counting, add a data label and delete the other trials.

 

Tip #2

• The tripwire also carries the ability to analyze movements exterior to the entryway depending on if the camera’s field of view covers the foot traffic at the front entrance. If it does, it can count the number of people who pass by the entryway on the outside and use it for an entry conversion rate.
• To enable this we have to draw a tripwire from the location of the foot traffic back to the entryway.

 

Variety of Tripwire Shapes

It is important to find the best fitting tripwire for your entrance so that you achieve the best count.

DIRECT ENTRANCE

If doors open outside, place double tripwire without corners along the entrance line in proportion to the exact length as the entrance doors, or a bit longer.  

 

SECURITY BARRIER ENTRANCE

Place double tripwire around the security barriers so that the security barriers are in front of the tripwire. The corners of the double tripwire will cover a flow of people on the sides.

 

OBSTACLE

Tripwire can be shaped in the appropriate manner according to the entrance.    

 

Examples of Correct and Incorrect Tripwire Set-up

Example #1

Incorrect: Ends of the tripwire are NOT  “closed”. Bottom line (2nd line) of the double tripwire is NOT longer than the upper line (1st line). This creates space allowing for people who pass through it to not be counted.

Correct: Ends of Tripwire are “closed”. Bottom line (2nd line) of the Double Tripwire should be a bit longer than the upper line (1st line) to avoid space.

Example #2

Incorrect: Tripwire is NOT drawn across the entire entryway. If an item is situated in the entryway the tripwire should cover the entire space to avoid inaccurate counting of people.

 

Correct: Tripwire is drawn across the entire entryway. Tripwire should cover any space between the doors of an entryway to avoid creating corner space where inaccuracy in counting may occur.

 

Example #3

Incorrect: Narrow tripwires are subject to miscounting. The double tripwire in the example above is very similar to a single tripwire. It can count a person who instead of entering, takes a quick “peek” inside.

Correct: Creating wider space between the first and second line of a double tripwire is key in receiving the most accurate results.

Example #4 

Incorrect: Tripwire like this may cause inaccurate counting due to the opening and closing of the doors. To make sure this does not occur, move the tripwire deeper inside the store, and away from the doors; or make it wide enough that when a door is opening it is not interfering with tripwire.

Example #5

Correct: Overcounting of people can be a result of shadows. Just as the camera should be placed in an area with regard to harsh sunlight or bright glares, the tripwire should not be placed where shadows of people walking by may pass through it.