What is the minimum PPM required for 'Detection' according to the DORI standard?

The minimum PPM (Pixels Per Meter) required for 'Detection' according to the DORI standard is 25 PPM. This standard is part of the guidelines for evaluating the performance of video surveillance systems, particularly in terms of their ability to detect objects at varying distances.

In the context of video surveillance, 'Detection' refers to the system's capability to identify the presence of an object within the camera's field of view. A resolution of 25 PPM indicates that each square meter can resolve 25 pixels, which is deemed sufficient to discern the basic shape and presence of a person or object in the footage. This level of resolution allows operators to reliably notice an object that may require further investigation.

Higher PPM values are designated for other categories in the DORI standard, such as 'Recognition' and 'Identification,' which require greater detail for more specific tasks. Hence, 25 PPM is the minimum requirement that establishes a foundational level for effective detection within a video surveillance system, ensuring that the technology in use is capable of fulfilling its primary role in security and monitoring.