Blur:Box blures edge of frame

Hello there!

I’ve put an image on the track and used Blur:Box for some effect over the duration of the clip.

It somehow also made a blurry frame around the image which doesn’t look good, looks like a blurry grey border. The background of the image is white so it’s quite noticeable.

Can this be improved?

A picture paints a thousand words. If you post an image of the problem you would make it easier for someone to understand the problem better and be able to help you sort it out.

Maybe you have something like this where the Box Blur effect creates blended edges of the picture:

If that is the case, I recommend to try one of the other blur filters that handle edges differently:

Available blur filters can be found by searching for “Blur” in the filter search box:


As a supplement of information about the Blur: Box filter:

If you add a Alpha Channel Adjust filter (mode: Blur) under Blur: Box, you’ll still get blurry edges, but they will look much better.

(Right-click on the GIF and open it in another window or tab to se it at 100%)

Sometimes you can also add the Unpremultiply Alpha filter under Alpha Channel Adjust, for a different blur effect on the edges. It removes the dark areas in the blurred edges.

(Right-click on the GIF and open it in another window or tab to se it at 100%)

These filters, Alpha Channel Adjust and Unpremultiply Alpha can also be used with with Blur: Gaussian, Blur: Exponential and Blur: Low Pass when you need to add a blurry edge.
Here’s an example with Gaussian Blur:

(Right-click on the GIF and open it in another window or tab to se it at 100%)

I want the effect of Blur:Box, looks like a shaking motion.

Can you show us the image you want to apply this motion blur effect on ?

I got carried away a little bit and tried to apply a motion blur to a flying rocket using the files belllllow, 5 tracks and a few filters, including Blur: Box:

Rocket on white background image:

This video clip of a comet-like object with a trail of smoke:

A view of the Shotcut window:

And the result:


Bravo, très réussi.

Bravo, very successful. :+1:

1 Like

Isn’t the meaning of bellow is a deep roaring shout or sound, however, I think you got a typo in the haste of typing a post. Next time remember to remove that extra él or L, perhaps it’s a modern style to write below that I didn’t know till now.

(It’s post 1)

Merci !

él ?
I edited my post. Won’t happen again.

1 Like

Seems to be super correct, even more correct than the founder of engllllllish. He would be proud of you… Lol!.. :rofl::rofl::rofl:

(It’s post 3)

Wow, @MusicalBox , that is clever and impressive. Bravo.

1 Like

This topic was automatically closed after 89 days. New replies are no longer allowed.