How to remove bright streaks that a mask keeps confusing with skin

Last updated 2026-09-17 · 8 min read

Tell Vizard Agent where the bright streaks are and, just as importantly, what else in the frame is bright. It then builds the mask against the background behind the streak rather than on brightness alone, and shows you which pixels it would change before it renders anything at all.

What is the short version?

A white streak is easy to describe and hard to select. Every automatic way of finding it comes down to "the bright pixels", and in a shot with hands, faces and paper in it, the bright pixels are mostly not the streak.

Tell Vizard Agent which edge of the frame the streaks run along.
Name everything pale that must survive — skin, paper, highlights.
Ask to see the mask on sample frames before the full render.

What do you need before you start?

The clip and an honest description of what is near the marks. Vizard Agent can measure the streaks itself, but knowing in advance that they cross an arm or sit against a sheet of paper changes which approach it reaches for first and saves a whole failed attempt.

The clip. The original file, not a re-encode.
Where the streaks sit. Bottom edge, one corner, across the middle.
What is bright nearby. Skin, paper, a white wall, plastic.
Whether they move. With the camera, or across the frame.
Whether they appear throughout. Or only in some shots.

What do you type into Vizard Agent?

Put the exclusions in the instruction, not in the follow-up. The difference between a mask that works and a mask that eats an arm is the sentence naming what stays, and Vizard Agent treats that sentence as a constraint it has to test against rather than as a preference.

Prompt

Remove the white flowing streaks along the bottom of this video. They cross skin and a sheet of paper in some shots — neither of those may change at all. Show me exactly which pixels your mask would touch on a few sample frames before you render the whole clip.

Variants worth knowing:

"They cross skin." The one fact that changes the method.
"Show me the mask first." A preview of pixels, not of picture.
"They come and go." Tells it to check when the streaks leave frame.

What does Vizard Agent actually do?

Here is the Vizard Agent sequence on a clip with white streaks along the lower edge, some of them lying across a forearm and a page. The interesting part is how many times the mask is rebuilt before a single final frame is rendered.

Samples frames and pulls larger ones for close inspection.
Measures the streak area across the length of the clip.
Tests a localised repair on the streak region — and reads the error when the filter fails.
Tries a tighter mask and reviews what it changed.
Checks when the streaks leave the frame, so later shots are not treated.
Generates candidate brightness masks on representative frames.
Reviews which pixels the mask would change — and finds skin and paper in it.
Refines the mask to exclude skin and paper rather than lowering its strength.
Previews the content-aware repair on samples before committing.
Renders, then compares the repaired region against the original.
Tracks the largest patch through the close-up, setting its boundary on a coordinate grid.
Runs playback checks on the uploaded copy and returns to the exact flagged timestamps.

Step seven is the one that earns its place. Vizard Agent does not look at the repaired picture and ask whether it looks right; it looks at the mask itself and asks which pixels are inside it, which is the only way to catch an arm being included before it has been painted over.

Step eight is the decision the whole job turns on. The obvious fix for a mask that grabs too much is to make it weaker, and a weaker mask just leaves faint streaks behind. Vizard Agent narrows what the mask is instead, using the background behind the streak to separate it from skin of a similar brightness.

Step three is a real failure, kept in the list on purpose. The first filter Vizard Agent tries does not run, it reads the error, and the attempt costs a few seconds rather than a bad render.

What does the result look like?

The lower edge of the frame reads as ordinary background, with no soft blurred band where the streaks used to be. Arms, faces and paper are untouched, the audio track is the original one, and Vizard Agent has compared before-and-after frames at the timestamps its own playback check flagged.

When does this not work well?

Some bright marks cannot be separated from what they cross. If a streak has the same colour and brightness as the skin underneath it and no clean background edge, there is nothing for Vizard Agent to build the mask against, and a patch will show as a smudge that travels.

Streaks the exact tone of the skin. No edge to work from.
Heavy compression. The streak's edges are already smeared into the background.
Streaks over fine detail. Hair, lace, printed text.
Very fast motion. The repair lags behind what it is covering.
Streaks covering most of the frame. That is a grade, not a repair.

How do you fix a result that came back wrong?

Say which of the two failures you are looking at — leftover streak, or damage to something that should not have changed. Vizard Agent moves the mask in opposite directions for those two, so guessing costs a full render.

"There is still a line at 0:19." The mask is extended at that timestamp.
"Her arm went soft." Skin is excluded from the mask and it is rebuilt.
"The paper has a grey patch." The boundary is set on a coordinate grid.
"It flickers between shots." The streak is re-tracked through that shot.

How does Vizard Agent compare to doing it yourself?

By hand this starts as a two-minute job and turns into an afternoon. You draw a box over the streak, the repair blurs the arm inside the box, you shrink the box, and now the streak is half there. The loop is the problem, and each turn of it costs a render.

	By hand	Vizard Agent
Finding the streaks	By eye, shot by shot	Measured across the clip
The mask	Brightness, or a drawn box	Built against the background behind it
Checking	Watching the output	Which pixels the mask contains
Skin and paper	Hopefully outside the box	Named exclusions, tested
Leftovers	Found on a later viewing	Flagged by playback QC, then fixed

Common questions

Why does a brightness mask fail here? Because skin and paper are bright too. Vizard Agent uses the background behind the streak instead.

Can I see the mask? Yes. Ask Vizard Agent for the mask on sample frames before any render.

Does the audio change? No. Vizard Agent keeps the original track and checks it after the render.

What if the streaks only appear at the start? Vizard Agent checks when they leave the frame and treats only those shots.

Do the streaks have to be white? No. Any consistent bright artefact can be measured the same way.

What if one is much bigger than the rest? It gets its own pass. Vizard Agent tracked the largest patch separately here.

Will the repair move with the camera? Yes, if it needs to. Vizard Agent maps the positions across the clip first.

How long does it take? Longer than a blur, because most of the time goes on the mask rather than the render.

Can it do several streaks at once? Yes. They are mapped together and repaired in one pass.

What if the result still looks soft? Tell Vizard Agent where, and the mask is narrowed at that point.

Does it re-encode the whole video? It renders a clean master, then verifies the uploaded copy plays as expected.

Can it handle a moving close-up? Yes. The patch is tracked through the shot rather than fixed to one position.

What if I cannot describe where they are? Give Vizard Agent a timestamp and it will find them from the frame.

Is there a faster version? A simple crop, if the streaks only ever touch the edge of the frame.