Automatic Cropping With Pic Scanner – Get it Right

Automatic cropping is Pic Scanner’s key effort-saving feature. But what if your photos are cropped incorrectly, split in random places or look skewed? You could re-scan, but the tips below will help you get accurate results every time.

  • The most common mistake? Many beginners get #4 wrong
  • These tip apply to Pic Scanner as well as Pic Scanner Gold

Automatic cropping tips

1) Use plain background:

Lay photos on a plain white or single color surface. Multi-color background won’t work well. In the pictures below, #1 may lead to wrong cropping, while #2 and #3 are fine:

2) Mind the gap between photos:

When scanning multiple photos together, keep a 1/2-inch i.e. 1-2 cm gap between them. If pictures are too close together, the app may not recognize them as separate images. In the screen shots below, #1 is wrong, #2 is fine:

If your photos are in albums, you can scan an entire page at a time – again, provided that there is a gap between the photos. See examples below – what’s OK and what isn’t:

scanner-gap

3) Ensure contrast between photos and background:

It helps to have some color difference between the photos’ edges and the background. So, for example, to scan a snow scene, place it on black or another solid color background (Not white).

scan-contrast

4) Keep photos fully visible:

In your scan, a bit of the background surface must be visible all round the photos. If any photos reaches the edge of the viewfinder frame or extends beyond it, cropping will be wrong.

Below, #1 is wrong (Left edge touching the viewfinder’s edge), #2 is good. Note that #3 is also correct, but here the camera is held too far away  from the photo, and will result in lower resolution scan.

scan-distance

Scanning in accordance with the above four tips should resolve cropping errors in 90% of the cases. If problems still persist, see the following “outlier” situations:

Perspective distortion:

If scans are distorted, this indicates that you didn’t have the camera centered above the photos and level with them. Pic Scanner has built-in automatic perspective correction, but try to avoid holding the camera off-center or at an angle to the photos. In the illustration below, the photo on the left doesn’t look rectangular because the camera is tilted. Usually our apps will correct for this, but in some cases you may end up with distorted or wrongly cropped results.

skewed-scan

Long and narrow photos

Photos with (Length > 2.5 times width) may not be cropped correctly. These can be cropped manually from Originals screen.

Photos with straight-line color gradients

See the photo below. Pic Scanner auto-crops photos by detecting where their edges lie. But if a photo contains prominent straight lines, these can be mistaken for edges.

image

Below, we have highlighted these edges in yellow:

unnamed

  • If cropping is wrong (or a photo is missed out), you can crop manually from the Originals screen (Tap Original thumbnail > Trim > Adjust size and position of the cropping rectangle > Crop. The photo will be saved on Cropped screen.
  • Can you turn off automatic cropping or share originals? Automatic cropping is a big effort-saver, and the above tips should help you get it working. However, you can also transfer Originals to Cropped screen for sharing: On Originals screen, tap Select. Tap one or more photos to select them. Tap Move, then Move to Cropped.

Extra tip for scanning album pages

If the photos in your albums are too close together (but not touching each other), you can still auto-crop them. Even 6-8 mm gap is enough for the app to recognize them as separate photos. Just scan one or two photos at a time instead of the entire page, by holding the camera closer to the page (See below: Scanning 2 photos at a time). With a bit of trial and error, cropping will work.

album1   album2 

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If your photos were cropped wrong and you can’t figure out why, just send us the cropped and original photos. We will analyze and guide you on what to do.

Blog of Pic Scanner, the photo scanner app for iPhone and iPad. Tips on how to digitize old family photos

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