I recently helped a friend put together a short film called ‘Sequestration‘. We filmed it on my Canon 600D / T3i with Sigma 30mm and Tokina 11-16mm lenses. Aside form a bunch of issues with lighting and focusing we were pretty happy with the end result.
One of the things that was really apparent in some of the shots was that look of ‘colorful’ digital noise – and this was something I wanted to minimise. Here’s a technique that I used.
Before and After shots
Above you can see the rainbow coloured noise minimised without any real damage to the original image.
How to remove those DSLR noisy coloured artifacts.
In Adobe After effects you simply import your footage then add the following Effects.
- Channel Combiner
- Channel Blur
- Cannel Combiner (again)
- Unsharp Mask (optional)
Here are the settings that I used
So what is happening here is we add a Channel Combiner effect. This lets us take our RGB image and change it to the YUV Color space. This essentially turns the Red Channel into the LUMINANCE channel and the Green and Blue channels into the UV Channels (which have the COLOR information).
Our eyes respond more to contrast than to color – so what we do is add a little blur to the color channels (G and B) using the Channel Blur effect. This softens out the colored noise but we still have our luminance channel to hold everything together so we don’t end up with a really softened out mess.
Then lastly we simply add another Channel Combiner and convert back from YUV to RGB.
Optionally you can add a little sharpening. I usually do this as I have the sharpness setting in my camera turned off (becuase it makes things ugly otherwise) – and then I sharpen things slightly again in AE or Premiere.
Learn more about the Channel Combiner
To learn more about the Channel Combiner then there is a great tutorial over at Motionworks.com.au by Maltaannon. Check it out here.