"Back in the day" security pro's talked about the percentage of the screen an object occupied in order to be able to detect, classify, recognize, or identify a particular subject or object in a scene. At MidChes, we refer to these items of interest as "targets." At that time we had resolutions that were quite low. So the idea of "zooming in" on a freeze frame of recorded video to investigate an incident was far-fetched at best.
As years have passed and technology has moved forward by leaps and bounds, we now talk about "pixels on target." With incredibly high resolution IP camera capability today, "zooming in" on an area of recorded video and gathering meaningful evidence is much more realistic.
Our friends on Hollywood TV had interesting capabilities many years ago. Check out this security industry eye-opener for yourself for a quick laugh:
Understanding how many pixels are "on target" ensures that our designs meet client expectations, not those of Hollywood.
For example, if you want to identify a license plate at a specific distance, you will need the license plate to be the size of a certain number of pixels wide by a certain number of pixels high in order for the image to be clear enough on your screen to be able to read the license plate. This is also important to software platforms that take that information and turn it into an automated process that can compare good/bad lists. Plus, we also consider lighting at the scene, headlight glare, and other key configuration considerations.
So, in the Bosch world, when we talk about being able to classify an object, you will need to have 12 pixels on the target for every square foot of surface area of the target. And each level of DCRI has a specific pixel count associated.
To learn more about DCRI and pixel counts required to meet your expectations, click here for a quick and easy read.
In the meantime, if you have an IP camera calculation that you need quickly and with accuracy, Rick Buehler and Joe Veiga have a pixel calculator at the ready to help you. Give either of them a ring at (410) 612-9640 or support@MidChes.com.
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