How to remove outliers

Info

Film outliers are usually black or white speckles. We detect them by comparing a frame with 3 previous and 3 next frames. If 6 pixels are within a band (as determined by the "constant band width") and the black or white value is very different (as determined by the "minimum distance") it is declared an outlier and removed.

Settings

A number of options that you can adjust to remove the outliers and keep real pixels.
All values are on a scale 0-255 where 16 = black and 235 = white.

Constant pixels before and after

The number of previous and next frames considered when detecting outliers. Choose 2 for videos with lots of specks or 3 for less dirty videos.

Constant band width

The maximum distance between any two of the pixels before and after the pixel considered ("in constant band" condition).

Minimum difference

The minimum brightness difference between any of the constant pixels before or after and the pixel considered.

Black or white specks only

Only remove specks whose brightness exceeds the minimum for white specs or is below the maximum for black specks.

Minimum white

The minimum brightness of a white pixel that is to be removed.
The default is 200 (=84%).

Maximum black

The maximum brightness of a black pixel that is to be removed.
The default is 52 (=16%).


In order to find more specks:
lower "Constant pixels before and after"
raise "Constant band width"
lower "Minimum distance"
uncheck "Black or white specks only"
lower "Minimum white"
raise "Maximum black"

Troubleshooting

You may need to treat different parts of a movie with different settings.
A speck is not removed if it is at the same location as a speck in a preceding frame or following frame. In this case you can try moving one or two nearby frames between the specks before processing the movie, then move them back in the result movie.