Keywords: Ringing artifact example.png ringing artifacts showing a quarter-circle of light gray on dark gray with 3 levels of artifacts on each side overshoot ring 1 ring 2 Produced by taking the original image a single sharp transition without artifacts then upscaling by 2× via a Lanczos-3 filter sharpening via unsharp masking radius 1 amount 10 1000 then upscaling again by 2× with Lanczos-2 own Created with GIMP 2010-05-23 Nils R Barth File Ringing artifact example - original png “ original without artifacts cc-zero Artefacts errors |