Scan Picture to PDF: Printed Photos and Phone Cameras

To scan a picture to PDF when it is a printed photo, use a flatbed scanner at about 300 pixels per inch at the original size, or a phone scanner held square above the print, then save the scan as a PDF or keep the image file. A photo is not a document: tone and color matter more than text, and the best result starts from a clean, flat print.

Scan picture to PDF: resolution for printed photos

The Federal Agencies Digitization Guidelines Initiative (FADGI) says 300 pixels per inch at the original size is the minimum to reproduce a photograph well, and adds that accurate tone and color in the scan matter as much as resolution or more. For a standard 4 by 6 inch print, 300 pixels per inch is 1200 by 1800 pixels. Very fine engravings may need 800 or more, which is a case for archives. At home, scan at 300 and increase only if you plan to enlarge the photo.

Scan picture to PDF with a phone

Phone scanners avoid the need for a scanner. Google’s Photos help describes the PhotoScan app: hold the phone directly above the print, take the picture, then move the phone so the circle lines up over each of the four dots, which captures the edges. The page says the app needs Android 7.0 or later and was last updated several years ago, so check whether it is still offered. Apple’s guide describes the scanner in the Files app (More, then Scan Documents) and in Notes (paperclip, then Scan Documents), which are built for documents but can capture a picture; Apple’s page does not say which file format the scans are saved in.

Lay the print flat on a surface that contrasts with its edges, keep the phone parallel to the print, and avoid overhead light that reflects off a glossy surface.

Save a scanned picture as PDF or as an image

A PDF holds the scan on a page and is easy to send; the image file is better as the master because it can be edited and printed at its own size. Keep the original scan and make a PDF copy. For converting scanned image files, scan image to PDF covers resolution, OCR and size. Digital photos, as opposed to prints, follow different advice in photo to PDF, and scanning apps are covered in picture to PDF app. Pictures found on websites are a separate case, described in save picture as PDF.

FAQ

What resolution should I scan a printed photo at?

About 300 pixels per inch at the original size, per FADGI, and higher if you want to enlarge it.

Can I scan a photo with my phone?

Yes. PhotoScan, the Files scanner and Notes can all capture a print; check the file format of the result.

Should I save a scanned photo as PDF or JPG?

Keep the image as the master and make a PDF copy for sending.