Measure which corresponds to the dimensions represented by one Pixel.

In case of (generated) images without physical relevance, the pixel size may be arbitrary and consequently omitted.

Include reference to step size when defined

Pixel size is determined through a calibration process.

Practically pixel size may be given with different physical units - for example with a 2-dimensional length unit. In case of spatial arrays a square pixel shape is tacitly assumed in case of a 1-dimensional length unit.

The term voxel is used for three-dimensional discretizations and as such is related to pixels and pixel size.

We stress that pixel size and detector pixel size are two distinct concepts and are not synonymous. For clarity please refer back to the definitions of pixel and detector pixel.