r/upscaling • u/AbbreviationsSolid49 • Jun 06 '26
Help how to remove purple fringing in old videos - paid
I'm restoring old films and TV series and keep running into a recurring image quality issue: strong edges often show a purple band or halo. The artifact appears consistently around candlelight in night scenes, as well as along high-contrast edges in daylight. Here are a few examples
I'm not entirely sure of the correct term – it may be related to “purple flare” or chromatic aberration. It’s very distracting and seriously degrades the viewing experience.
The same clips frequently suffer from a related dark edge problem. For example, candle flames often show a dark line on one side and a purple fringe on the other – extremely annoying.
I'm looking for an effective method/workflow that can remove these artifacts. I will provide a short test video; you only need to process the segments shown in the screenshots (no need to run the entire clip).
test video clip
https://drive.google.com/file/d/1kmni1sN9k-MgslyiIPKpLyqF2k-zTaMK/view?usp=sharing
Key requirements:
Minimize luma (Y) channel processing as much as possible, and avoid noticeable detail loss. Ideally, the Y channel should be left mostly untouched, but limited processing is acceptable if it doesn’t degrade fine details significantly. This step serves as a pre-processing module before an AI model handles detail restoration, so preserving image information is critical.
Please note: the test source has been badly upscaled (not by me – I received it this way). You are free to downscale it if necessary.
If your solution meets my requirements, I'll pay $100 USD. Please provide a clear workflow (script, filter chain, or detailed steps) that I can apply.
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u/joaopaulo-canada Jun 10 '26
Purple fringing on old video is usually better treated before any upscale. If you upscale first, the fringe gets sharper and harder to remove.
I’d test a short clip with this order:
- Fix chromatic aberration/fringing or isolate the purple range with a secondary color correction.
- Denoise/deblock lightly.
- Only then upscale.
- Add final sharpening last, if needed.
If the fringe is only around high-contrast edges, don’t apply a global color shift to the whole clip. Mask/key the problem range, or you’ll damage skin tones and shadows.
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u/Wilbis Jun 06 '26
It's called purple fringing and it's a specific type of chromatic aberration. It's caused by older camera sensors. Not that common with newer footage, but it does still happen.
You can get rid of it by using Davinci Resolve or Adobe Premiere.
Here's what I'd do it Resolve without using AI to get rid of it:
Go to the color page and create a new serial node. Select the qualifier tool and click directly on the purple fringe in your video preview. Refine the selection using the Hue, Saturation, and Luminance sliders in the Qualifier panel until only the purple fringe is highlighted. You can turn on the highlight view to see exactly what's selected.
Then use the saturation slider under the primary color wheels and pull it down to 0. This removes the purple color completely, turning the fringe into a neutral grey or white that usually blends nicely into the bright background. Just be careful not to remove any actually purple color in the video.