Raising the quality setting to cure banding that is actually caused by 8-bit depth, which changes nothing.
Compression
Banding
Also called colour banding, posterisation or gradient banding. Here is what it means, when it changes what you export, and what people get wrong.
CompressionRuns on your deviceUpdated 10 August 2026
The short answer
Banding is when a smooth gradient breaks into visible steps or stripes instead of blending. It happens when there are too few distinct tonal values to describe the transition, either because the image has limited bit depth or because compression has merged near-identical tones into one.
Updated
The short version
Banding at a glance
| Quick fact | Detail |
|---|---|
| Also called | Posterisation, contouring |
| Two causes | Too few tonal levels, or lossy quantisation |
| 8-bit channel | 256 levels per colour channel |
| Standard fix | Dithering, or a little added noise |
| Prevention | Edit in 16-bit, reduce to 8-bit last |
Slide the table sideways to see every column.
Is it bit depth or compression causing it?
Both can, and the fix differs, so it is worth working out which you are looking at.
Bit depth banding comes from running out of numbers. An 8-bit channel offers 256 levels. A studio backdrop that fades from light grey to slightly lighter grey might only cross thirty or forty of those levels, and if that fade is spread across 2000 pixels, each level occupies a stripe roughly fifty pixels wide. The step between one level and the next is then large enough to see as a hard edge. Editing makes it worse: a strong curves or brightness adjustment stretches a narrow range of values over a wider one, pulling the existing steps apart.
Compression banding comes from quantisation. A lossy encoder rounds the coefficients that described the gentle variation across a block down to zero, so the whole block becomes one flat value and the boundary with its neighbour becomes a visible edge. Reducing an image to an indexed palette does the same thing more bluntly, which is why GIF, capped at 256 colours per frame, posterises gradients badly.
Why does adding noise fix it?
Because the eye is extremely good at spotting a straight boundary and quite bad at spotting a scattered one. Dithering deliberately mixes pixels from the two neighbouring tonal levels along the border between them, in a random or ordered pattern. Nothing new is added to the gradient, but the hard line dissolves and your vision averages the mixture back into a smooth transition.
A small amount of film-style grain does the same job on a photograph, which is one reason lightly grainy images survive compression better than perfectly clean ones. Both tricks cost a little file size, since noise is expensive to encode, but it is usually a better trade than a striped sky.
Where does banding show up most?
- Seamless studio backdrops and vignette falloff behind products, which are exactly the gentle low-contrast gradients that use the fewest tonal levels.
- Clear skies and sunsets, particularly after a strong contrast or saturation adjustment.
- Artificially blurred backgrounds, where the blur creates smooth gradients that were not in the original data.
- Flat brand colours and generated gradient graphics, which have no natural noise to hide the steps.
- Screens and images pushed into HDR, where a wider brightness range spread over 8 bits leaves even coarser steps.
If you are producing gradients yourself, work in 16 bits per channel while editing and only reduce to 8 bits at export, after all the heavy tonal adjustments are done.
What people get wrong about banding
Each one is a real failure mode, not a style preference.
Applying strong contrast or exposure curves to an 8-bit file and only noticing the pulled-apart steps after export.
Removing all grain from a photograph for a cleaner look, which strips the natural dithering that was hiding the steps.
Judging a gradient on a laptop panel that dithers in hardware, so the banding only appears once someone else opens the file.
Questions people ask
Banding, answered
The follow-up questions people search for once they have the definition.
Why does my white background have visible stripes?
A studio sweep is a very shallow gradient, so it uses only a handful of the available tonal levels and each step covers a wide stretch of pixels. Compression then flattens whole blocks to a single value, hardening those steps into stripes.
Can you remove banding from an image you already have?
Partly. Adding a small amount of noise or a subtle blur across the affected area breaks up the edges and usually makes them acceptable. You cannot recover the missing intermediate tones, so severe posterisation from an indexed palette rarely cleans up fully.
Does saving as PNG prevent banding?
It prevents compression from adding any, because PNG is lossless. It does not help if the banding is already in the pixels from limited bit depth or heavy editing, since PNG stores exactly what it is given.
Same cluster
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Background removal
Background removal separates the subject of a photo from everything behind it and discards the rest, leaving either a transparent cut-out or the subject on a new backdrop.
Bicubic interpolation
Bicubic interpolation works out each new pixel by fitting a smooth cubic curve through a 4 x 4 block of sixteen surrounding pixels.
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