What Is Dori?

DORI is an acronym for Detection, Observation, Recognition, and Identification. It is a reference standard tailored for cameras based on the IEC EN62676-4:2015 international standard. It is used to assess the camera’s visual range. This measurement method is typically expressed in PPM (Pixels per Meter), defining the count of pixels within a one-meter width at a designated distance from the camera. By employing these PPM values, cameras can be objectively evaluated based on their sensor/lens combination, enabling an unbiased comparison of each camera's long-distance magnification capability and verifying its ability to meet customer performance requirements.

The DORI standard encompasses four distinct levels: Detection, Observation, Recognition, and Identification.

Detection:

The Detection level is set at 25 PPM, allowing for reliable and straightforward determination of the presence of a person or vehicle, though few details will be discernible.

Observation:

The Observation level, set at 62 PPM, offers distinctive details of an individual, such as distinctive clothing or unique physical characteristics. This level also provides a broader perspective of the activities surrounding an incident, providing context and assisting in comprehensive incident analysis.

Recognition:

The Recognition level, established at 125 PPM, aims to ascertain, with a high degree of certainty, whether an individual appearing in the footage is identical to someone previously observed.

Identification:

The Identification criterion, defined at a standard of 250 PPM, enables the unequivocal identification of an individual. This clarity is so precise that it confirms a person's identity beyond any reasonable doubt, making it especially useful in high-security scenarios and investigations.

What Factors Will Affect DORI?

A camera's focal length and resolution will significantly influence its DORI performance. At the same level, longer lenses or smaller sensors result in a narrower field of view, while shorter lenses or larger sensors provide a more comprehensive view. Thus, a longer focal length allows for a greater distance to be seen, which means that an object of the same 1m size will achieve the same PPM at a greater distance with a camera having a longer focal length than a shorter one. Therefore, for a given DORI effect, a long-focal-length camera can see farther, but at the same time, its field of view is more constricted.

Another critical factor influencing the performance of long-distance cameras is sensor resolution, which determines the level of detail captured within the camera's field of view. For instance, 2MP and 8MP cameras have a fourfold resolution difference. This means that, at the same approximate distance of 1 meter, the 8MP camera, with four times as many pixels as the 2MP one, can depict the scene with greater clarity. Similarly, the 8MP camera can observe from a greater distance at the same PPM value.

How to use DORI to choose a suitable VIGI Camera?

When selecting a camera, it's crucial to first establish the required DORI image quality based on the type and size of the surveillance area.

For instance, when facial surveillance is required to ensure clear images of faces are captured, selecting the appropriate camera based on the Identification level is ideal. Similarly, choosing a camera at the Identification level is advisable in settings like parking lots where clear license plate information is needed.

When capturing general human and vehicle shapes at a store entrance or similar setting, opt for the Recognition level when selecting the Camera to ensure clear images of passing vehicles and pedestrians are captured.

When the expansive surveillance area and only human or vehicle shapes must be captured from a distance, the Observation level is suitable for selecting the appropriate Camera model.

Additionally, should additional functionalities be required, it is essential to consider the specific needs and elevate the DORI level of the Camera accordingly.

Lastly, the appropriate focal length range will be determined based on individual usage preferences and the field of view needed for the surveillance area. Select the model that meets the requirements at that focal length.

Below is the DORI List for different VIGI cameras; we can refer to that list to filter the camera first.