Image overlays

An image overlay is a picture laid over the map: a site plan, an architect's drawing, a scanned map or a drone photo. Once it sits in the right place you can draw and measure over it as over the satellite imagery. Everyone who opens the project sees it.

Overlays are listed in the Layers panel. Adding, moving and deleting them needs permission to edit the project.

Add an image#

1. Move the map to the place the picture shows.
2. Press layers Layers on the right side of the map, then add_photo_alternateAdd image overlay.
3. Choose a PNG or JPEG file.

You can also drag the picture from your computer onto the map, or choose it with folder_open Import in the top toolbar. One picture is placed at a time: if you choose several, only the first is used.

A KMZ file from Google Earth can bring its image overlays with it, already in place. See importing files.

Place it on the map#

Once you have chosen the picture, the map turns north-up and flat, and the magic button shows add_photo_alternate: the next two clicks place the picture.

1. Hold Shift to show the crosshair (or right-click the map to turn it on) and click where one corner of the picture goes.
2. Move the crosshair. The picture stretches from that corner to the crosshair, so you can see where it will land.
3. Click where the opposite corner goes.

The picture is uploaded to the project and the magic button goes back to add Add. To give up before the second click, press Esc or the red clear button next to the magic button.

The picture fills the rectangle you draw: it does not keep its own proportions, and it always stays north-up (it cannot be rotated). A plan drawn at an angle to north needs to be rotated in an image editor first.

Adjust an overlay#

Open the overlay's panel: press its row in the Layers panel, or click the picture on the map when you are not drawing. The panel shows a preview and these controls:

• the name at the top: click it to rename the overlay. It starts as the file's name, without the extension;
• North-east and South-west: the exact coordinates of the picture's top-right and bottom-left corners, in the coordinate format chosen in the settings. Type new values to move a corner precisely. The change is saved a moment after you stop typing.
• editEdit: back to the map to redraw the picture. Its top-left corner stays where it is; move the crosshair to set the opposite corner and click.
• delete_foreverRemove: deletes the overlay, after you confirm.
• Transparency: drag the slider to the right to make the picture see-through, so the imagery shows beneath it, and back to the left to make it solid again. The panel shows how see-through it is, from 0 % (solid) to 100 %. The setting is saved for everyone.

People who view a shared project can open the panel to see the overlay, but cannot change it.

If you delete an overlay by mistake, press undo Undo in the bottom toolbar to bring it back.

MBTiles maps#

An MBTiles file holds a whole map cut into tiles for every zoom level, as drone-mapping and GIS software export it. Unlike a single picture, it already knows where it belongs and stays sharp as you zoom in.

1. Press layers Layers, then mapAdd MBTiles overlay.
2. Choose an .mbtiles file.

The file is uploaded to the project and the map zooms to the area it covers. Its tiles are drawn over the map at the zoom levels the file contains, and the layer appears in the Layers panel as MBTiles map, named after the file without its extension.

To open an MBTiles map's panel, press its row in the Layers panel or click the map inside it. There you can rename it, make it see-through with Transparency, or remove it with delete_foreverRemove. You can also remove it with delete_outline next to it in the Layers panel. See the Layers panel.