Scanning a sheet in overlapping passes

Why scan in passes

A big map sheet usually does not fit a scanner bed in one piece. Instead of shrinking it into one blurry photo, capture it as several horizontal bands that share an overlapping band. Dibber joins the bands into one seamless Stitched map image — a process we call Stitching — and from there it behaves exactly like any other map image. Each of the bands you capture is a Scan strip.

The recipe: an A3 sheet in three passes

The default recipe is three Scan strips — top, middle, bottom. Here is what to do at the scanner:

1. Lay the sheet flat and keep the same orientation throughout. Slide the sheet between passes to move each band across the scanner bed — never rotate it.
2. Scan three horizontal bands: top, middle, bottom. Each pass should cover a little more than a third of the sheet, so consecutive bands share part of the map.
3. Leave an overlap band of roughly 10–20% of each Scan strip's height shared with its neighbour — about 2–3 cm on A3 in three passes. This is practical scanning guidance, not a hard rule: the overlap band is the shared content Stitching matches on, so give it enough to recognise.
4. Use the same resolution and scan settings for every pass.

Stitching accepts 2 to 8 Scan strips. If a matched overlap turns out thinner than about 10% of the strip height, Dibber flags it as thin so you know where a Seam — a join between two Scan strips — may look rough. Strips with no shared content to match at all fall back to an assumed centre-aligned placement you can nudge yourself in the review before accepting.

Accepted formats

JPG, PNG, WebP and PDF — mixed freely in one Stitching run. The easiest path is a multi-page scanner PDF: scan the sheet in passes straight into one PDF and upload that single file. Each page becomes one Scan strip, in page order — so scan the top band first. Individual photos work too; just pick them all in the Multi-scan stitch mode (“Choose Scan strips”).

Multi-scan stitch is part of Dibber Plus

Multi-scan stitch is a Dibber Plus capability. On Plus — and during the free 14-day Plus trial — it is part of the ordinary map import flow, under the Multi-scan stitch mode; on the Free plan that entry stays visible with an upgrade offer. For the plan detail, see Free vs Plus: limits & usage. Everything else in this guide — how to capture the passes and what makes a good overlap — applies exactly the same.

What you get

The result is an ordinary map image: matching landmarks attach to it and alignment works unchanged — see aligning a map image. For the full list of supported import formats and size limits, see importing route & map files.