How to remove shadows from a scanned document
The most common problem with phone scans isn't focus, it's shadow: yours, your phone's, or a dark corner where the light doesn't reach. A gray blotch makes a document look careless and prints as a smudge. You can avoid most shadows, and a good scanner app removes the rest.
- 1
Scan in even light
Diffuse light from above or a window works best. Avoid a single bright lamp to one side.
- 2
Stand so your shadow falls behind you
If the light is overhead, lean so your head and phone aren't between the lamp and the page.
- 3
Use the Auto look
Auto evens out shadows and uneven light while keeping colors true, so the paper comes out an even white.
- 4
Adjust the strength
Use the enhancement strength slider if a shadow is still visible, or choose B&W for a crisp black-and-white page.
Why phone scans get shadows
To keep a page in frame, you hold the phone directly above it, which puts both of you between the page and any overhead light. A flatbed scanner lights the page from underneath; a phone can't, so the software has to correct for it.
ScanMojo tells the paper from the ink and brightens the paper to an even tone across the page, which removes the gradient a shadow leaves without washing out faint text.
When to keep the original
For photos, artwork and anything where color is the point, choose Original. It keeps the camera's colors and only crops and straightens the page.
Questions
Can I remove shadows from a photo I already took?
Yes. Import it from Photos, and the same shadow correction applies.
Should I use the flash?
Usually not. Flash causes glare on glossy paper and a bright hot spot in the middle. Even room light gives a better result.