Can scanning software detect a photo of a screen or a photocopy?

Yes, this is specifically what document liveness detection is designed to catch, and it's a meaningfully important capability given how common both screen-photo and photocopy fraud attempts are in remote identity verification scenarios, where a business can't physically hold and inspect the document the way a bank teller or hotel clerk traditionally could.

Screen-photo detection typically relies on analyzing artifacts that are characteristic of photographing a digital display rather than a physical document. Moiré patterns, the wavy interference patterns that appear when a camera photographs a screen's pixel grid at certain angles and distances, are one common signal.

Unusual glare or reflection characteristics from a screen's glossy surface, distinct from the way light reflects off a document's paper or laminated surface, is another. Some systems also look at the color and brightness characteristics typical of digital displays versus printed materials, since screens and paper reproduce color differently in ways that can be detected algorithmically.

Photocopy detection looks for a different set of signals: the absence of physical security features that only exist on a genuine document (certain printing textures, holograms, elements visible only under specific lighting conditions), along with characteristic flatness, color shifts, or contrast differences typical of photocopied materials compared to an original document. Black-and-white photocopies are generally easier to catch than color ones, since the absence of color alone is often a strong signal, though color photocopies still typically lack the physical security features and precise color reproduction of a genuine document.

Both checks generally work best as part of a live capture flow rather than a static image upload, since a live camera feed gives the software more information to work with, multiple frames from slightly different angles, for instance, than a single already-captured static image would provide.

ScanDoc's document liveness detection checks specifically for these screen-photo and photocopy signals as part of its scanning flow, aiming to confirm that a genuine physical document, not a photo or copy of one, was actually presented during the scan.