What's the optimal setup for measuring parking space utilization?

The ideal camera position can see the parking spaces to be analyzed with few obstructions similar to this example:

Please read this article on defining the floor plane 3D Grid.

Camio provides the ability to measure utilization across individual parking spaces using existing cameras.

Any camera connected to Camio can include a 3D grid that defines the layout of the space in three dimensions in the camera's Field of View (FoV). Along with the grid, one can also specify zones on the camera that will serve as a trigger for the measurement process.

With the grid and the trigger zone in place, Camio detects the utilization of individual parking spaces each time there is significant motion in the trigger zone. For example, in a parking lot with a single entrance, a trigger zone set at the entrance will enable utilization measurement every time a car enters or exits the lot.

These are the recommendations to help Camio perform the most accurate measurement of parking space utilization.

Camera Placement

The most important element in this setup is the placement of the camera such that it best captures the parking spaces and the vehicles.

• The camera should have a complete view of the ground.
• The camera's Field of View (FoV) should extend to the ground such that it captures the wheels of the cars as they touch the ground.
• The camera should not be centered facing the parking slots and instead should view them at a certain horizontal angle so that the cars in the front cannot completely occlude smaller cars behind them.
• The horizontal angle should not be too steep.
• The camera should be looking downwards at the slots with a relatively wide angle.
• The camera should not be easily blocked by some cars such that other cars behind are not visible. 

Sample cases describing setup scenarios

		Vertical angle is not too steep. The ground and cars are at a reasonable horizontal angle from the center. Individual slots can be observed in full detail.
		Camera is placed at a location such that certain slots are blocked by trees or other objects.
		Camera is placed right in front of the slots, so the front cars can almost completely occlude those in the background.

 

Drawing the Grid

The 3D grid helps Camio understand the difference between individual slots in the parking lot. Some key optimizations while drawing the grid are as follows:

• The grid should be mapped as closely to the parking slots as possible.
• Each grid tile should map to a single parking slot.
• The slots should neither be too large or too small.
• In case of different parking lanes, individual single row grids should be created.
• Base and wheels of cars should uniquely map to the grid tiles.

 

Sample cases describing good and bad grid layouts

		Individual horizontal grids are mapped to each parking row. Each grid tile is almost exactly mapped to the parking space. In case of filled slots, the tiles retain unique mapping of the base of the car.
		By extending the grid to multiple rows in the parking slot, it may map well to certain slots, but doesn't extend the same way, therefore making the mapping inconsistent.

 

Drawing the Trigger zone

The trigger zone lets Camio know when it is time to measure utilization. Some key optimizations while drawing the trigger zone are as follows:

• The zones should be limited to key areas of entrance.
• The marker '!countparking' should be used on the zone in order to make it a parking trigger zone.
• The zones should not be too large, otherwise it may incur a lot of noisy hits
• The zones should not overlap much with individual parking slots.

 

Sample cases describing good and bad trigger zones

		Individual zones are created for each entrance. The zones are marked with the trigger !countparking The zone sizes are large enough to capture motion. The zones are limited to entrance and do not overlap with parking slots.
		By extending the zone to multiple multiple entrances, we end up overlapping with an entire parking slot, which may cause errors.