How to cover a number plate with your own text that tracks the car

Last updated 2026-09-22 · 8 min read

What is the short version?

You want to post the clip without your registration in it. A blur announces that there is something here you are hiding; a short word sitting exactly where the plate is says nothing at all, which is the point of asking Vizard Agent for a fitted replacement instead.

1. Tell Vizard Agent to cover the plate and what it should say.
2. Say explicitly that nothing else should be blurred.
3. Expect it to track the plate rather than cover a region.

What do you need before you start?

The clip and the word you want on the plate. Vizard Agent measures the plate itself, but knowing in advance whether the car drives away, turns across the frame or stays parked tells it how much tracking the shot is going to need before any of it starts.

• The clip. The original file.
• What it should read. A name, a nickname, a word.
• Whether the car moves. Towards, away, past.
• What must stay sharp. Everything else, usually.
• Whether other plates appear. Parked cars in shot.

What do you type into Vizard Agent?

Say "nothing else" and mean it literally. Requests to cover a plate are routinely answered with a general privacy pass that softens faces, other cars and half the street, and what you get back is a clip that looks censored rather than one that looks clean.

Prompt

Variants worth knowing:

• "Fit exactly where the plate is." Size and position, not a box.
• "Move with the car." Tracking, stated as a requirement.
• "Do not blur anything else." The instruction people forget.

What does Vizard Agent actually do?

Here is the Vizard Agent sequence on a clip where the car drives down a road and away into the haze. Almost every step on the list is measurement rather than rendering, because the plate gets smaller and fainter in each successive frame until there is nothing left to measure.

1. Samples frames to locate the plate.
2. Extracts close views at several times to measure the replacement area.
3. Maps the plate coordinates across the full frame for a tracked overlay.
4. Uses the plate's own colour to compute its bounding box automatically.
5. Opens full-resolution frames with the plate centred to fix the exact geometry.
6. Validates the automatic boxes visually so the mask hugs the plate and not the road behind it.
7. Estimates the farther positions from the reliable early frames.
8. Builds a coordinate-marked review of the hazy middle section to finalise the path.
9. Zooms into the moment the plate becomes partly obscured to avoid a bad position there.
10. Follows it through the lane shift and on to the last clearly visible frames.
11. Renders the tracked replacement with the audio preserved.
12. Finds the overlay defaulting to the frame origin, fixes the escaping in the tracking expression, and re-renders.
13. Re-checks the early, middle and distant positions on the finished file.

Step six is the one that separates a clean job from an obvious one. An automatic box found by colour will happily include a yellow line on the road or a reflection on the bumper, and a replacement sized to that is visibly bigger than the plate.

Step seven is the part nobody enjoys. Once the car is far enough away the plate is a smudge a few pixels high, too small to measure reliably — so its position is projected from the frames where it could be measured rather than guessed frame by frame.

Step twelve is an honest bug. The first render put the word in the corner of the frame because a character in the tracking expression was read as a separator; Vizard Agent inspected the generated expression, escaped it properly and re-rendered.

What does the result look like?

The same clip, your plate reading the word you chose, at the plate's own size and angle, shrinking with it as the car moves away. Nothing else is softened — faces, other cars, signs and the road all stay exactly as filmed — and the audio is untouched.

When does this not work well?

Some shots will not take a fitted replacement. A plate at a sharp angle, one that is mostly obscured, or footage so compressed that the plate is a grey blur gives nothing to measure, and a small blur is the honest answer there.

• Steep angles. The replacement has to be distorted to match.
• Mostly obscured plates. Behind a tow bar, a trailer, a bike rack.
• Very low resolution. No stable geometry to track.
• Fast cuts between shots. Each shot needs its own tracking.
• Several cars. Each plate is its own job.

How do you fix a result that came back wrong?

Give the timestamp where it looks wrong to you. Vizard Agent adjusts the measured path at that point rather than rebuilding the whole overlay from scratch, and in practice the early frames are already right even when the distant ones have drifted off the plate.

• "It slips off at the end." The far positions are re-estimated from the reliable frames.
• "The box is bigger than the plate." The mask is tightened to the measured geometry.
• "You blurred the driver too." The pass is limited to the plate alone.
• "The word looks pasted on." Its tone and edge are matched to the plate.

How does Vizard Agent compare to doing it yourself?

By hand you either blur it in two minutes and accept how it looks, or you spend an evening keyframing a rectangle down a road. The second is genuinely fiddly, because the interesting frames are the ones where the plate is too small to see what you are keyframing.

Common questions

Can it just blur the plate instead? Yes, if you prefer — Vizard Agent will, though a fitted word looks less hidden.

Will it work on a parked car? Yes, and Vizard Agent is far quicker at it — one position rather than a path.

Can it do several cars? Yes. Vizard Agent treats each plate as its own tracked object.

What if the plate is at an angle? Vizard Agent matches moderate angles; a steep one is harder to make convincing.

Does the audio change? No. Vizard Agent keeps the original track.

Can it keep the plate's colour and style? Yes. Vizard Agent matches the plate's own background so it reads naturally.

Is this for hiding someone else's plate? It works on any plate in your own footage, which is usually why people ask.

Should I use a real-looking registration? Better not to. A word or a name avoids implying a plate that belongs to someone.

What about the reflection of the plate? Rarely an issue, but tell Vizard Agent if the shot has one.

Can it cover a VIN or a sticker too? Yes, the same tracked approach works for any small fixed detail.

Will it survive a crop to vertical? Yes. Ask Vizard Agent to do the crop after the replacement.

How small can the plate get? Down to a few pixels; beyond that Vizard Agent projects the position.

Can it do a whole vlog of driving shots? Yes, shot by shot, since each one needs its own tracking.

How do I check it? Step through the last few seconds; that is where a tracked overlay drifts.