Guide

Your first overlay, step by step.

From a drone photo to a finished image or video with property lines on it. Most people are done in a few minutes.

Before you start

You'll need:

  • A Mac running macOS 14 Sonoma or later. Apple Silicon and Intel Macs are both supported, with a separate download for each. See the download page.
  • DJI drone photos. Straight off the drone, or edited first, as long as the drone's metadata is kept. Color, exposure, retouching and resizing are fine. Cropping, straightening, lens correction or perspective fixes change what the camera saw and will misplace the lines, so do those after exporting from Line by Air.
  • An internet connection. Line by Air uses it for satellite imagery, parcel data and ground elevation.

Install

  1. Download the right version for your Mac from the download page.
  2. Open the .dmg file.
  3. Drag Line by Air into your Applications folder.
  4. Open Line by Air from Applications. It's signed and notarized by Apple, so it opens like any other app.

First launch

The first time you open Line by Air, it shows the Terms of Use. Read them, then click I understand. You can read them again any time from Help → Terms of Use…

Trial or licence

You don't need a key to start. The free trial works straight away, and exports carry a small trial watermark. If you've bought a licence, enter your key from Help → Licence… More in Licence and trial.

1. Open a photo

  1. Drag a drone photo onto the Line by Air window, or click Browse files.
  2. To work on several shots from the same flight, select them all at once. They appear in the photo list on the left.

Line by Air reads the camera, position, altitude and heading from the photo. If a photo has no DJI flight data, it can't place lines on it. See This photo has no DJI flight data.

2. Choose the terrain

Line by Air asks What type of terrain?

  • Flat terrain — level ground with little change in height.
  • Sloped terrain — hills or slopes. Line by Air uses real ground elevation so the lines follow the land. It will ask where the drone took off.

When in doubt, choose Sloped. You can switch later with the Flat / Sloped button at the top of the window.

3. Mark the takeoff

This step only appears for sloped terrain. Your drone measures its height from where it took off, not from the ground under the photo. Knowing the takeoff spot lets Line by Air correct for hills.

On the map, the white Drone marker shows where the photo was taken from. Then choose one of two options.

Use the flight log (most accurate)

  1. Click Use the flight log.
  2. Select the DJI flight logs for the shoot. They're .txt files named like DJIFlightRecord_…txt. You can select several.
  3. Line by Air finds the flight the photo was taken on and places the green Takeoff marker at its exact takeoff point.
  4. Click Continue.

Line by Air remembers the folder you chose. Next time, it checks that folder automatically and fills in the takeoff for you if it finds the right flight.

Where are my flight logs? The DJI Fly app keeps a flight record for every flight on the phone or controller you flew with. Copy those .txt files to your Mac, for example with a cable or file sharing, and keep them with the photos from that shoot.

DJI encrypts its logs. Line by Air unlocks each log once through its server. Only the log's encrypted key blocks are sent, never your flight path.

Pick it on the map

  1. Click Pick it on the map.
  2. Click the spot on the map where the drone took off. A green Takeoff marker appears. Click again to move it.
  3. Click Continue.

Clicking the map works either way, so you can also fine-tune a takeoff that came from a flight log.

4. Find the lot

Open the Lot tab. Choose Single lot or Multiple lots, then pick a method.

Address

  1. Type the address into Property address.
  2. Click Look up lot.

Auto-detect

  1. Set Distance from drone. The default is 400 m (about 1,312 ft).
  2. Click Detect lots. Line by Air finds the lots around the drone's position.

Address lookup and Auto-detect work across the US.

Import

Click Choose KMZ, KML, or GeoJSON file and pick a file from a surveyor or county GIS site. The shapes in the file become lots you can select.

Draw

  1. Click Start drawing on the map or Start drawing on the photo.
  2. Click to place each corner.
  3. Double-click to finish, or click the first corner to close the shape.

Corners snap to nearby parcel corners. Hold Shift to place a corner freely. Import and Draw always work, wherever the property is.

Select the lot

Click a lot on the map to select it. It turns orange, and its lines appear on the photo, following the terrain. On sloped terrain you may see an elevations progress message for a moment while Line by Air gets the ground heights.

5. Style the lines

Open the Style tab.

  • Choose All lots to style everything at once, or Individual to style one lot.
  • Under Outline, set the Color and Weight. Pick solid, dashed or one of the glow styles.
  • Under Fill, raise the Opacity to shade the lot. It starts at 0%, so you only see the outline. You can also fill the area outside the lots instead.

6. Align, if needed

Most of the time the lines land in the right place. If they're a little off, use the Align tab.

Auto Align

  1. Click Start picking.
  2. Click a clear spot on the photo, such as a fence corner or the edge of a driveway.
  3. Click the same spot on the map.
  4. Repeat until you have 4 pairs. Spread them across the photo, not in a line.
  5. Click Solve. Line by Air shows the average error, so you can see how good the match is.

Manual adjustments

  • X offset and Y offset slide the lines left, right, up or down.
  • Rotate turns the lines up to 45° either way, around the center of the lots.
  • Yaw, Pitch and Altitude nudge the camera position itself.
  • Distort (multiple lots only) lets you drag four corners to warp all the lots together.

Reset alignment undoes all of it.

7. Add labels

Open the Labels tab.

  • Add at center puts a label in the middle of the photo. Drag it into place and type your own text.
  • Add from map lets you click a real spot on the map.
  • Anchor to ground pins a label to its real-world location. It stays in the right place across photos and can show its distance from the lot.

8. Animate and export

Animate

In the Animate tab, choose how the lines draw themselves in and how long it takes. Click Play preview to watch it on the photo.

Export

  1. Open the Export tab.
  2. Choose Photo (JPG) or Video (MP4).
  3. Pick an Aspect and a Resolution.
  4. Leave Add a disclaimer to the export on if you'll share it. It reminds viewers the lines are approximate.
  5. Click Export photo or Export video, then choose where to save it.

You can also export Per-lot transparent PNGs (no photo), one image per lot, for use in your own designs.

Before exporting, Line by Air shows a short Before you export reminder of the Terms of Use. Click Continue to go ahead. You can tick Don't show this again before exporting to skip it next time.

Check the photo's data

The Info tab shows what Line by Air read from the photo: the camera Model and Lens, GPS position, Altitude (AGL), Camera pitch and Heading. If something looks wrong here, the lines will be off too.

9. Save your project

Choose File → Save Project (⌘S). This saves a .lba project file with your lots, styles, labels and alignment.

  • The project points to your photos rather than copying them. Keep the photos alongside the project file.
  • Line by Air autosaves as you work. If it ever quits unexpectedly, it offers to recover your work next time.
  • File → Open Project… (⌘O) opens a saved project.
  • File → New Project (⌘N) starts fresh.

Working with several photos

A project can hold many photos of the same property.

  • Add more with + Add in the photo list.
  • All photos share the same lots and styles, so you set them up once.
  • Each photo keeps its own alignment.
  • Keep one flight per project on sloped terrain. All photos in a project share one takeoff spot, so a flight that launched somewhere else needs its own project (File → New Project). Line by Air warns you when photos come from different flights. See troubleshooting.
  • Replace, at the top of the window, swaps in a different photo.

Export them all at once

  1. Tick the photos you want in the photo list.
  2. On the Export tab, choose Photo or Video.
  3. Click Export all selected and pick a folder.

You get one file per photo, each with its own alignment applied.

Licence and trial

Free trial

No key needed. Trial exports carry a Line by Air · Trial watermark. The trial ends after 14 days or 3 properties, whichever comes first. A property is one project.

Enter a licence key

  1. Choose Help → Licence…
  2. Click Enter Licence Key…
  3. Paste the key from your purchase email. It looks like LBA-XXXXX-XXXXX-XXXXX-XXXXX.

The same window shows your plan. Pay-as-you-go plans also show the credits you have left.

Pay as you go

Each property uses one credit the first time you export it. Re-exporting the same project, with more photos, videos or angles, is free for 30 days.

Moving to another Mac

Open Help → Licence… on the old Mac and click Deactivate This Mac. Then enter your key on the new one.

Updates

Line by Air checks for updates once a day when it starts, and offers a Download link when there's a new version. To check yourself, choose Help → Check for Updates…

Tips for accurate lines

Line by Air is not a survey. Lines can be off by several feet, and more on steep ground or far from the drone. Use it for marketing and visualization, not for legal, construction or boundary decisions.

  • Fly higher and look down more. High, steep shots line up better than low, shallow angles.
  • Choose Sloped for anything that isn't truly flat.
  • Use the flight log for the takeoff. It's more precise than clicking the map.
  • Keep the full frame. Edit color and exposure all you like, but crop or straighten after exporting, not before.
  • Use Auto Align with 4 well-spread points if the lines are a little off.
  • Undo freely. The undo and redo buttons sit at the top of the window, next to Replace (⌘Z and ⇧⌘Z).

Next steps