Saving Noisy Footage: The Easy Way and the Hard Way
Noisy shot? No problem. Here are two ways you can clean it up in post-production.
We’ve covered noisy footage in-depth before, but what can we do to save our footage when we’re out of options, and we’re dealing with severe noise?
In this article, we will briefly go through the main ways popular programs and plugins reduce distracting noise before taking a look at two powerful ways to reduce noise in your footage.
Here’s a shot that I underexposed pretty severely on a documentary shoot a few years back.
To get this closer to a deliverable image, we’re going to need to boost the levels on the image a little bit.
After bringing the image up by about four or five stops, it’s looking much better, but we’ve introduced a lot of noise. We’ll need to clean that up before we deliver it to the client. Let’s look at a few workflows for reducing this noise.
Adobe Production Suite
So, the easy way to rid your footage of unwanted noise is by using the dynamic link between Adobe Premiere Pro and Adobe After Effects.
Shutterstock contributor Robbie Janney made a killer two-minute video breakdown on using dynamic link between AE and Premiere for noise reduction. Check it out, and give it a try; it could save you some time compared to the more involved method below.
If dynamic link doesn’t work for you, let me introduce you to one of the most commonly used noise reduction plugins on the market today: Neat Video. It offers some pretty outstanding results without much hassle.
You can break down the workflow in the Neat Video User Guide to a few basic steps:
- Add effect.
- Prepare noise profile.
- Adjust filter settings.
1. Add Effect
To apply Neat Video to your clip, navigate to the effects panel in your editing program, search for “reduce noise,” and then drop the Neat Video effect onto the clip you want to adjust. After that, simply click the “setup” button next to the effect, and the Neat Video plugin will launch in a new window.
Let’s set our viewer windows to YCrCb. This will help us to preview each of the component “image channels” in the recorded footage.
For readers new to image channels, every video or still is actually a composite of three distinct image channel feeds blended together to form recognizable shapes and colors.
The Luminance Channel
The luminance channel often gets shortened to “Luma” or “Y,” and it contains all of the illumination and contrast data of the image. Viewing the luma channel on its own just looks like a black-and-white version of your clip.
The Chrominance Channels
All of the color information in your shot is stored in one of two “Chrominance” channels. The chrominance channels often get shortened to “Chroma” or “C.” The chroma channels are subdivided into Red color information and Blue color information. These channels are most often labelled “Cr” and “Cb.”
The chroma channels are a bit harder to get to and interact with. We will need to know how to view and interpret them, however, as the majority of distracting noise in any type of footage usually lives in one of these two chroma channels, as illustrated in the gif above. This is especially important as we begin noise reduction.
You will see these three image channels grouped together under the shorthand “YCbCr.”
Once we have applied the “Reduce Noise” filter to our clip and have our viewers set to YCbCr, it’s time to begin working on our footage.
2. Preparing a Noise Profile
Neat Video reduces noise by building a noise profile for the specific camera or shot. While pre-made camera profiles are available online, you will always get better results by manually reducing noise.
Building a Noise Profile with the Calibration Target
The most common way to build a noise profile in Neat Video is using the built-in “calibration target.” During this process, Neat Video is sampling regions of the frame that contain little to no important detail in an effort to determine the structure and type of noise in the shot.
To begin profiling your shot, simply click the auto-profile button. You will see a square appear over your footage. This square will be blue, yellow, or green. The colors represent small, medium, and ideal sample regions to profile the noise in the shot. You always want to aim for a green square over an appropriate region of consistent noise.
Sometimes Neat Video doesn’t select the best area.
In this case, you will need to select a new area in your frame. When selecting regions, look for featureless areas of the frame that also contain noise. When profiling, try to keep the quality of your sampled region above 60 percent. I wasn’t able to hit 60 percent for this shot, but got it close enough.
Once you’re happy with your targeted region, click “Auto Fine-Tune” and then “Noise Filter Settings.”
3. Adjust Filter Settings
Now that we’re in the filter settings, let’s take a quick look at each of the panels and what they’re controlling.
Manual noise reduction in Neat Video is done in three panels: “Noise Levels,” “Noise Reduction,” and “Sharpening.”
Both the Noise Levels and Reduction panels contain two types of controls: noise frequency and noise color.
The noise frequency controls are divided into high, medium, and low frequencies. High-frequency noise usually looks sharper and more grain-like than the blocky and blotchy medium and low frequencies.
The YCrCb controls allow users to specify the image channels suffering from noise and apply necessary reduction without affecting the fidelity of the others.
Think of the noise levels panel as Neat Video asking you what type of noise is in your shot. Take a moment to analyze your footage — is the noise in high, medium, or low frequencies? Is it luma or chroma noise?
Once you’ve established the noise structure in the shot you want to save, tweak the sliders representatively.
The workflow for the Noise Reduction panel is very similar to the Noise Level’s workflow. Adjust the controls to be roughly in line with your Noise Levels settings, and then tweak and preview until you’re pleased with the results.
The sharpening panel changes the control scheme up a little bit. To enable sharpening controls, select a channel to sharpen. From here, simply tweak the sharpening frequency controls until you’ve brought a little life back to your footage after noise reduction.
All that’s left now is to apply the effect and return to your editing program to double-check the results in context.
And rendering. Lots of rendering.
Looking for more post-production tips and tricks? Check out these articles.