Parking garages are a key area for using surveillance cameras. Thefts, assaults, vandalism and accidents are among the many incidents that cameras can help solve.

Monitoring parking garages effectively is more challenging than it first appears. On the plus side, garages are generally enclosed and laid out in long lanes conducive to surveillance camears. However, most parking garages have openings on the side that expose the garages to sunlight. Also, garages depend on artificial lighting that can create great variation of lighting across the scene.

Below is an image from our testing scene showing the presence of outdoor opening and artificial lighting. The cameras were mounted at ceiling level aimed directly down the middle of the driving lane to capture people and cars moving through the garage:

In the test, we used a kit of 7 different cameras (including SD, 720p, 2MP, 3MP and 5MP from Arecont Vision, Axis, Bosch, IQinVision and Sony) to better understand the tradeoffs for ourselves.

The overhead image and map below demonstrates the coverage, distances and pixels per foot at different positions:

Then we analyzed a series of scenes to see how performance varied across the cameras. We digitally zoomed each camera to the same level to see the differences. See an example scene comparison from our parking lot test.

We conducted our analysis across 16 scenes. They are:

• Midday Back Lighting (Far Vehicle)
• Midday Back Lighting (Near Vehicle)
• Midday Even Lighting (Far Human)
• Midday Even Lighting (Near Human)
• Twilight Back Lighting (Far Vehicle)
• Twilight Back Lighting (Near Vehicle)
• Twilight Back Lighting (Far Human)
• Twilight Back Lighting (Near Human)
• Nighttime Color (Far Vehicle)
• Nighttime Color (Near Vehicle)
• Nighttime Color (Far Human)
• Nighttime Color (Near Human)
• Nighttime BW (Far Vehicle)
• Nighttime BW (Near Vehicle)
• Nighttime BW (Far Human)
• Nighttime BW (Near Human)

Inside the Pro section, we analyze and show the differences captured in each scenario. We focus on the significant practical problems that significant lighting variations may cause.