ANPR at the Factory Gate: Accuracy, Cost and Certified Models
Can gate ANPR read Indian truck plates? Plan for about 80% on standard plates and 60% on non-standard ones, the SLA baseline in Ujjain Smart City's tender (RFP USCL/404, 1 Nov 2025). That needs about 300 px/m on the plate, under 30° to the vehicle and a fast shutter. As of 15 Oct 2026, one STQC-certified model is named ANPR.
Last checked: 15 Oct 2026. The gate layout is assumed; densities, angles and model data are sourced.
Verified against
- Axis, License plate capture, June 2021.
- Dahua, ANPR key technology page.
- AxxonSoft, camera requirements for LPR (Axxon Next 4.5, 2021).
- CMVR Rules 50–51, AP Transport Department; Rule 50 in Puducherry circulars (2011, 2014).
- Puducherry HSRP order (2012) and HSRP SOP (2024).
- Ujjain Smart City, ITMS RFP USCL/404, 1 Nov 2025, p. 51.
- Kerala Police, ANPR tender ET-01/2021/TR, 31 Jan 2021.
- CP Plus CP-UNC-TT41L3-VMD-Q datasheet (22-12-2025), STQC ER/29, ONVIF DoC (28 May 2026).
- BIS CRS security-ER CCTV list, read 9 Oct 2026.
- Matrix, ANPR and weighbridge solution pages.
- Checked 15 Oct 2026.
Gate ANPR requirements: value and source
| Requirement | Value | Source |
|---|---|---|
| Pixels across the plate | 100–150 px | Axis white paper, §5 |
| Pixels across the plate (alternative) | 70–250 px; EU 130–250 px | Dahua ANPR page |
| Pixels per character height | ≥10 px, preferably ≥20 px | AxxonSoft requirements |
| Character height on Indian plates | 65 mm (all vehicles except two- and three-wheelers) | CMVR Rule 51 table |
| Plate sizes in use | 500×120, 340×200, 200×100, 285×45 mm | Puducherry G.O.Ms.No. 9 (2012) |
| Density to plan for | ~300 px/m (20 px ÷ 0.065 m = 308; 100 px ÷ 0.34 m = 294) | derived from the rows above |
| Angle to vehicle | total under 30° (Axis); horizontal under 30° (Dahua, Axxon); vertical up to 45° (Axxon) | as listed |
| Plate angle in image | under 5° (Dahua); plate parallel to image edges (Axis) | as listed |
| Max shutter time, 30 km/h | 4.9 ms at 20°, 3.4 ms at 30° camera angle | Axis Table 8.1 |
| Minimum capture distance | 4 m at 10 km/h, 7 m at 30 km/h | Axis Table 7.1 |
| Resolution | 2 MP or less when LPR runs on the camera | Axis §1 |
| IR | Source close to the camera (plates are retroreflective); about 50% less IR reach at 1/500 s on a general camera | Axis §6 |
| WDR | Off for plate capture unless the camera spec says otherwise | Axis §8.3 |
Vendors disagree on pixels, so plan for at least ~300 px/m; the loading dock spec uses 300–440 px/m for its gate lane. Method: DORI guide.
What Indian plates do to accuracy
- Script. Under CMVR Rule 50, letters must be in English and figures in Arabic numerals. A plate in Hindi or a regional script breaks that rule, and an engine set to the Indian plate format should be expected to miss it. Matrix's ANPR profile has a "selected country" setting.
- Colour. Transport vehicles carry black on yellow; other vehicles carry black on white (Rule 50). Most trucks at a gate are yellow-plated.
- HSRP vs old plates. OEM dealers have fitted HSRPs on new vehicles since 1 Apr 2019 (Puducherry SOP, 2024). The plates are 1.0 mm aluminium to AIS-159:2019. Older trucks may still carry painted plates. Kerala Police's 2021 ANPR tender demanded a live demonstration on "both printed and hand-painted license plates". A factory buyer can ask for the same.
- Rear plate position. On a transport vehicle the rear mark sits on the right, no more than 1 m above the ground (Rule 50). An exit camera reading rear plates must therefore look low and from the right.
Published accuracy bars. Ujjain's RFP sets an 80% baseline for "Standard Roman Number plates (3 wheelers & above)" and 60% for non-standard ones. Below 60% and 40% respectively counts as a breach. Dahua claims "95%-98% with alphanumeric number plates", with no Indian test conditions stated. The CP Plus ANPR datasheet gives no accuracy figure.
Worked example: one inbound truck lane
Assumptions: the camera sits on a pole 3.5 m high and 1 m to the side of the lane centre. The truck's front plate is about 0.8 m above the ground, and the capture line is 8 m from the pole. That gives a vertical angle of atan(2.7 ÷ 8) = 18.6°, a horizontal angle of 7.1°, and an 8.50 m slant distance.
Formula: PPM = R ÷ (2 · d · tan(HFOV/2)), where R = horizontal pixels and d = distance in metres.
| Setting on CP-UNC-TT41L3-VMD-Q | Pixels × HFOV | Scene width (m) | px/m | px across 340 mm plate | px per 65 mm character |
|---|---|---|---|---|---|
| 4 MP stream, widest | 2688 × 44° | 6.87 | 391 | 133 | 25 |
| 2 MP stream, widest | 1920 × 44° | 6.87 | 279 | 95 | 18 |
| 2 MP stream, zoomed to 35° | 1920 × 35° | 5.36 | 358 | 122 | 23 |
At 2 MP the lens must be zoomed in to keep 20 px per character (18.6° tilt trims about 5% more). The datasheet lists a 10–50 mm motorised lens (HFOV 10°–44°), a 1/25–1/100,000 s shutter, 30 m IR from four 850 nm LEDs covering 1–2 lanes, and WDR at 140 dB. It also lists IP67, IK10 and –40 °C to +65 °C. For a lane at 20° and 30 km/h, Axis's table caps the shutter at 4.9 ms, so 1/250 s fits. Run other positions in the lens and DORI calculator.
Certified ANPR-named models (STQC and BIS), recomputed
Filter: confidence = primary rows of Mama's models.csv whose model name or certificate nomenclature contains "ANPR" (or LPR / number plate). The result is 1 of 196 STQC camera models and 5 of 2,006 BIS model rows, 4 of them in the security-ER column. The rows can be downloaded as CSV.
| Brand | Model | List and certificate | Valid to | Form and resolution |
|---|---|---|---|---|
| CP Plus | CP-UNC-TT41L3-VMD-Q | STQC ER/29 ("ANPR Camera"); BIS R-66000299 | 2028-11-20 (STQC); 2027-05-20 (BIS) | 4 MP, motorised 10–50 mm (datasheet); ONVIF S, T, G, M |
| Mediatronix | AI-ANPR-CAM-5M | BIS R-64000817, security-ER column | 2027-02-11 | Not stated in the BIS list |
| Mediatronix | AI-ANPR-CAM-8M | BIS R-64000817, security-ER column | 2027-02-11 | Not stated in the BIS list |
| Stellarview | SV-ANPR-RC-1 | BIS R-93048577, security-ER column | 2031-07-22 | Not stated in the BIS list |
| (brand blank; maker Finepro Solutions) | RT ANPR BD23AB | BIS R-81015369, analog column only | 2027-11-27 | Listed as analog, not in the security-ER column |
The name is the only ANPR signal these lists carry; a general certified camera can also feed server-side ANPR (certified CCTV finder).
Cost in ₹
No public ₹ price list for an ANPR camera from CP Plus, Prama or Matrix was found (checked 15 Oct 2026). Marketplace listings are not price lists and are not quoted. The one published tender figure found is Kerala Police's ₹75 lakh estimate for ANPR surveillance systems at 4 border locations (31 Jan 2021). That is district-police scope at border locations, with servers and integration included, so it is not a factory-gate price. Ask for a per-lane quote split into camera, IR, ANPR licence, pole and integration.
Integration with the weighbridge and the gate pass
- On the camera: the CP Plus datasheet lists a whitelist for barrier control, a "Vehicle Blocklist" alarm, 2 relay outputs, SDK/API and FTP/SFTP upload.
- In the VMS: Matrix describes three weighbridge cameras (plate, overhead container, scale) and a receipt with time, vehicle number, snapshot and weight. It lists SAP/ERP import/export and a CREAM module that exports ANPR data to third-party software.
- Owner use: match every plate read in and out against the gate pass. Flag a plate in with no pass, a pass with no exit read, and a dwell time beyond the norm. The money side is in the gate and weighbridge essay.
What breaks in a factory
- Dust and diesel film on the glass scatter IR; clean weekly.
- Trucks queue nose to tail and hide the plate behind them. Paint a stop line at the capture distance.
- Headlights blind a low camera, so mount it higher than the headlights (Axis).
- Tarpaulin ropes, tow hooks and bent bumpers cover front plates. Read the rear plate at the exit.
- After a power cut, the barrier needs a written fail-open or fail-closed rule.
- Hand-painted and regional-script plates will miss. Route them to the guard's manual entry.
When to call the installer / what to ask the vendor
Ask for a 7-day read-rate report on your own trucks, split by standard and non-standard plates (as Ujjain's SLA does) and by day and night. Ask for a demonstration on hand-painted plates, a measured pixel width across a plate at the capture line, and the exact output format the weighbridge software will receive.
Mama reads a factory's existing cameras over RTSP/ONVIF and tells the owner in plain language how long trucks waited and machines stood idle (askthemama.com). Leave an email or phone in the form below.
FAQ
Can ANPR read Indian number plates accurately? On standard plates it can, but not perfectly. Ujjain Smart City's 2025 ITMS tender treats 80% as the baseline for standard Roman plates and 60% for non-standard ones.
What is the right height and distance for an ANPR camera at a gate? Keep the total angle to the vehicle under 30° (Axis). At 3.5 m high, a capture line about 8 m away keeps the vertical angle near 19°.
Do I need a special ANPR camera, or will my CCTV do? A general camera can work if the plate gets 100–150 px, the shutter is fast and IR sits near the lens. A dedicated ANPR camera ships with these settings already tuned (Axis).