Ringing artifacts
In signal processing, ringing artifacts are artifacts that appear as spurious signals ("rings") near sharp transitions in a signal. Visually, they appear as "rings" near edges; audibly, they appear as "echos" near transients, particularly sounds from percussion instruments.
They have a number of causes, and their minimization is a criterion in filter design.
Examples
Imaging
JPEG
JPEG compression can introduce ringing artifacts, which is particularly visible in text.
| Image | Lossless Compression | Lossy Compression |
|---|---|---|
| Original |  |
|
| Processed by Canny edge detector |
 |
|
Chromatic aberration
Chromatic aberration can cause ringing artifacts,