What is DORI in CCTV? Understanding the Standard for Camera Selection
DORI stands for Detection, Observation, Recognition, and Identification. Defined under EN 62676-4, it is the international framework that specifies how much pixel density a CCTV camera must place on a subject to perform each of those four security tasks.
What is DORI in CCTV?
DORI helps security professionals evaluate camera performance against defined, task-specific criteria. Without this standard, camera selection relies on resolution figures that say nothing about what a CCTV system will actually capture at a given distance.
A claim of “high-resolution coverage” does not tell a facility manager whether the camera will identify a face at the reception desk or merely detect movement in a corridor. DORI replaces that ambiguity with a measurable threshold by tying each security task to a minimum pixel-density requirement. A camera meets the standard for identification at a specific distance, or it does not.
The framework rests on three things: the four task levels, the distance at which each is achievable, and the megapixel and lens combination required to reach it.
The Four Levels of the DORI Standard
The DORI standard defines four task levels, each requiring progressively higher pixel density on the subject. The thresholds set by EN 62676-4 are:
- Detection (25 pixels per metre): Confirms that a person or object is present. Sufficient for perimeter monitoring where the goal is to trigger an alert, not to identify who triggered it.
- Observation (63 pixels per metre): General characteristics become distinguishable at this density: clothing colour, vehicle type, direction of movement. Traffic monitoring and post-incident scene reconstruction both rely on this level of detail.
- Recognition (125 pixels per metre): Where staff or regular visitors need visual confirmation against existing records, this level provides enough detail to match a known individual to a reference image.
- Identification (250 pixels per metre): The highest threshold, providing sufficient detail to name a person not previously seen or to read a licence plate. Required at entry points, reception counters, and any zone where evidential-quality footage is the objective.
Each level roughly doubles the pixel density of the previous level. In practical terms, a small increase in mounting distance can move a camera from clear identification to marginal observation on the same subject.
What is DORI Distance and How is It Calculated?
DORI distance is the maximum range at which a camera achieves each of the four task levels. Every camera publishes four separate figures, one per level, and the gap between them matters more than any single number. A camera rated for identification at 8 metres may still detect movement beyond 80 metres on the same installation.
Three variables determine these distances:
- sensor resolution (megapixels)
- lens focal length
- and sensor size and pixel pitch.
Reputable manufacturers publish a CCTV DORI calculator that takes scene width, working distance, and required task as inputs and returns the correct camera and lens combination. Professional integrators rely on this during specification rather than estimating coverage by eye.
How Many Megapixels is Good for a CCTV Camera?
There is no universal answer, and the megapixel count a CCTV camera needs depends entirely on the DORI task and the distance involved. A 2MP camera can identify a face at close range but may only detect motion at the far end of a corridor. A 4K unit (8MP) extends every DORI distance proportionally, though only when paired with the correct lens and adequate network connectivity.
Here are three scenarios common in Singapore commercial properties to illustrate how this works in practice:
- Carpark entry lane (3 to 4 metres): Both the licence plate and the driver need to be identifiable, which means reaching the 250 pixel-per-metre threshold. A 4MP sensor or higher, with a lens matched to the lane width, typically achieves this.
- Reception lobby or turnstile: Identification is again the objective, but mounting height and angle affect pixel density on the face zone as much as the sensor specification itself. Resolution and lens must be chosen together to place 250 pixels per metre where it counts.
- Warehouse aisle or perimeter run: Detection is often sufficient here, which permits a wider field of view at lower pixel density and reduces the total camera count needed to cover the space.
Each scenario calls for a different sensor and lens combination, even within the same property. This is where the DORI framework earns its value: it converts a vague megapixel question into a specification decision matched to the actual coverage requirement.
Working With Sin Chew Alarm
Sin Chew Alarm runs DORI calculations for every camera position during the site survey, matching hardware to the security task before specification. This applies across every CCTV system and alarm system we design, with PoE switching and cabling specified to support the cameras, from single-tenancy offices to multi-building industrial estates.
With over 40 years of security engineering in Singapore, ISO 9001:2015 certification since 2005, and BCA Specialist Workhead ME04 L2 registration, our team specifies camera and lens combinations from measured distances and defined tasks, not default hardware packages.
Contact Sin Chew Alarm for a site assessment that applies the DORI standard to your property’s specific risk profile and coverage requirements.