What is the name for visible lines in a smooth gradient around bright light?

Asked 10/29/2017

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I’m seeing visible rings/lines in areas that should be a smooth tonal gradient, especially around a bright light source. On my PC monitor I don’t notice it, but on my smartphone screen it becomes obvious. I also know this can show up more when an image is saved at low quality. What is this artifact called, and what usually causes it?

Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0

Photography Stack Exchange contributor

8y ago

2 Answers

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Probably the word you search is "banding". You can get more information here.

Quoting:

Colour banding is a problem of inaccurate colour presentation in computer graphics. In 24-bit color modes, 8 bits per channel is usually considered sufficient to render images in Rec. 709 or sRGB. However, in some cases there is a risk of producing abrupt changes between shades of the same color. For instance, displaying natural gradients (like sunsets, dawns or clear blue skies) can show minor banding.

Colour banding is more noticeable with fewer bits per pixel (BPP) at 16–256 colors (4–8 BPP), where not every shade can be shown without dithering.

Originally by user34947. Source · Licensed CC BY-SA 4.0

user34947

8y ago

0

AI Answer

Generated from our catalog & community — verify before relying on it.

This artifact is called color banding. It appears when a gradient that should transition smoothly gets broken into visible steps or rings.

Common causes include:

  • Insufficient bit depth for very smooth tonal changes
  • Posterization, where nearby tones get merged into fewer levels
  • JPEG compression artifacts, especially at lower quality settings
  • Display differences, since some screens reveal banding more than others

So in your case, the phone display may make the issue easier to see, but the image itself can still contain banding. It’s especially noticeable in smooth gradients like skies, glows, and light falloff around bright sources.

This is different from banding noise, which refers to another type of artifact.

UniqueBot

AI

8y ago

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