Exploring the Realities of Megapixel Surveillance Technology

-- If you use 320H x 240V resolution cameras (0.07 mpix) you perform the computation by dividing 4,000 by 320. The result is 12.5, so let's put that at 13 cameras.

-- At 640 x 480, (0.31 mpix) you divide 4,000 by 640, and you come up with 6.25 cameras, so we round up to 7 cameras to make sure we've covered the scene fully.

-- If you're working with 1280 x 1024 (1.3 mpix) cameras, the scene would call for 3.25 cameras, Four cameras will surely cover the area.

-- As you move up the resolution ladder, you can compare cameras that create images equal to 2048 x 1536 (3 mpix). Using that resolutions, two properly positioned cameras will do the job.

The Realities of Pricing

Let's compare a non-megapixel installation for the parking lot with our highest level megapixel cameras in this example. A high quality camera made by an established manufacturer that delivers a 640 x 480 image has an MSRP of about $350. A high quality camera made by an established manufacturer that can deliver a 2048 x 1536 image has an MSRP of about $1249. A high-quality outdoor heater/blower housing has an MSRP of $225 and 100' of Cat 5 cable can be purchased for $20 (coax would be more expensive, but let's assume that we're comparing IP cameras that connect over Cat 5 cabling). Let's include $100/unit of labor to install a camera and do the math:

 

Obviously, this is a rather simple model; however, it demonstrates that megapixel systems prove to be less costly if you have a wide area to cover. Before you reject this analysis because we left out storage, be assured we will address that in an upcoming article in this series.

As a preview to that discussion, consider that while a megapixel image is certainly larger than a 640 x 480 image, with the smart camera tools available today it is not as large a difference as you would suspect. In fact, with all things kept the same in terms of compression, two images from a 3 megapixel camera typically take up less storage than seven images from a 640 x 480 camera. Again, we'll delve into the "why" and "how" of storage later in this series.

A Closing Note

We intentionally avoided a discussion about compression in this article as there are too many variables to consider. Nevertheless, end-users should beware of companies trying to convince you that they can compress images and not lose image quality. A good practice is to demand that anyone who proposes a system to you submit an actual JPEG image and an 8 x 10 glossy of a moving image captured at your site as part of the bid process. This will help ensure you get what you pay for.

About the author: Paul Bodell is vice president of sales and marketing at IQinVision, a U.S.-based vendor of high resolution/megapixel surveillance cameras. Bodell has been with the company since 2002, and has worked in the electronic security industry since 1994.