Today I’m taking a look at the Denoise effect,
which provides advanced noise removal and can dramatically improve the appearance of
your video. To put this to the test I’m going to be
using some old video footage we shot several years ago. This shot doesn’t look too bad
when you’re just looking at a still. But as soon as you hit play you notice this nasty
noise pattern in the background. All this noise movement distracts from the actor in
the foreground. This particular clip is pretty dark. To make
it easier to see the noise, I’m going to sling on the Exposure effect and boost up
the gamma to 1.7. You can really see now just how horrid this video is - we’re not just
talking about natural fine noise, there’s also awful artefacting going on around the
actor’s shirt. It’s actually unwatchable. Let’s get to work.
In the effects panel, search for denoise, then drag it onto the video layer. It’s
important to add denoise ABOVE any other effects, because you almost always want it to be working
on the original, unaltered source, where it’s going to have access to the maximum amount
of data. Effects are processed from top to bottom in a layer’s Effects group, so make
sure denoise is top of the list. Denoise’s interface is quite different to
other effects in HitFilm. Immediately you can see the Viewer has become darker, with
a highlighted box in the middle. This is the analysis box, which you use to show HitFilm
the unwanted noise. You want to find a flat-coloured area of medium brightness. Drag the corner
handles to reposition the analysis box. I’m going to go for this brown area on the
wall over here. Once you’ve positioned the box, hit the Analyse button in the Controls
panel. If you toggle the Denoise effect on and off
you should already see an improvement. In my example, check out the actor’s shirt,
which goes from a horrible, noisy mess to a less horrible noisy mess.
We can now provide HitFilm with additional data to improve the noise removal. In the
View menu, select Analysis Box. This will display the analysis box again. You now want
to move it to a darker area where noise is still visible, again aiming to find an area
with a flat, even colour. I’ll move it to this darker area on the right of frame.
Click analyse brightness to apply the new data, which is compared to the first analysis
and used to improve the results. The Frames menu shows how many frames are
sampled when denoising. Increasing the number of frames tends to create higher quality results
but impacts on performance, as additional frames are processed in order to provide more
data. Denoise isn’t magic and you still want to
aim for good quality footage in the first place. But certainly in the case of this shot,
it’s transformed an unusable shot into something with a lot more potential.
Here’s another example from the same old shoot. There’s again a lot of noise in the
shot, particularly visible when you watch it in motion. Again, I’ll apply denoise
and set the analysis box to a mid-brightness area, such as the paler part of the wall on
the right here. I’ll then switch the view to analysis box,
reposition it over this green cabinet and click analyse brightness.
There's been a definite noise reduction, but we've also lost quite a lot of detail in the
background. Note the edge of the cabinet and the detail in the blue door, both of which
look quote smudgy. This can be tweaked, first by switching to
8 frame samples, then by opening up the threshold group and increasing the keep edges property.
This retains more detail in the video while still trying to remove the noise. Toggling
the effect on and off shows the difference we’re making.
Third party denoise plugins tend to cost upwards of $100, so having a powerful denoiser built
right in is a great feature in HitFilm 3 Pro. Thanks for watching this tutorial and enjoy
your new, clean, sparkly footage.