Traditionally, mobile device cameras uses software algorithms to implement digital zoom. Compare alongside the optical zoom capabilities of DSLR cameras, the character of digitally zoomed images has non been competitive.
The Super Res Zoom technology inward novel released Pixel iii is unlike in addition to improve than whatever previous digital zoom technique based on upscaling a crop of a unmarried image, because it merge many frames straight onto a higher resolution picture.
This post service (from Google AI Blog) explain Super Res Zoom algorithms inward details:
See Better in addition to Further alongside Super Res Zoom on the Pixel 3