A Pixel is an Artifact: On the Necessity of Zero-Filling in Fourier Imaging

Xiaolu Zhu¹, Boguslaw Tomanek¹, Jonathan Sharp¹

Pixels visible as small square patches of uniform intensity do not represent object structures and are therefore artifacts. To quantitatively evaluate this we designed a Fourier-based method to decompose a pixelated visual scene into two parts: one representing the information in the original MRI k-space data, and the other the visible structure related to pixelized patchwork display. Results show that pixelized patchwork displays: A) attenuate actual high spatial frequency content (because patchwork display enforces image uniformity within each patch); and B) introduce artifactual high spatial frequencies (the patch edges). The solution is to zero-fill until individual pixels become invisible.