Georeferencer functionalities

This article gives a detailed overview of the abilities and functions of the georeferencer tool. When you select manual georeferencing in MapTiler Engine, you'll be taken to a new page.

Georeferencing your image

To georeference an image, all you need to do is to select a sufficient number of points from two maps – your image and online map, to align them. The absolute minimum is three points, however, the more control points you assign, the more precise the result will be. The best choice is to pick points on different parts of the map and do it as accurately as possible: this can be accomplished by choosing corners of buildings, crossroads, peaks, and other clearly identifiable points.

Georeferencing itself is done by clicking on one map and the same point on the other. The order doesn’t matter, you can first select a point in the online map and then on your image or vice versa. There is also an option to drop a point on one map and insert coordinates for the other one.

Available tools

The main window contains a search button in the very left top corner. By typing the village name and clicking the search button the referencing map will zoom to the selected place. The autocomplete function is available.

Below is the icon for map switch: you can select from the predefined ones or add a custom map service by pasting URL of WMS or TileJSON server.

Zoom in and zoom out buttons are available on both sides of the window: the left one work for referencing a map, right one for your image.

When you click on both a map and a picture you are georeferencing, in the middle bottom part of the screen appears a small window with coordinates you can manually change. By clicking on the gear icon on the right, you can also select if the coordinates are shown in EPSG:4326 or WGS84 format.

On the top, you can switch between Side by side view and an Overlay, which is available when at least three points are selected on both maps.

The coordinates button gives you an overview of already inserted points altogether with inaccuracy. Clicking on the coordinate will bring a selected point into central view, and hovering will highlight it.

The clip option allows you to crop your image before publishing. This path is referred to as a clipping path or a cutline.

The Gear icon on the top right corner gives you the option to change the way of transformation. All five available methods are described in a standalone manual.

On the right bottom, you can find the lock icon, which grips both maps together and reproduce any move or zoom on one map on the other.

The circle arrow straightens your image for viewing if it is distorted by georeferencing (this is just for easier orientation during the georeferencing process, it has no impact on the final product).

If you make any mistake during the whole procedure, you can always click on the wrongly inserted coordinate on the map and either move it to the correct position or delete it.

Now your image is georeferenced and you can continue with choosing the output format to store your map in.

Useful links

Map transformations
Georeferencing in MapTiler Engine
Choosing the output format of your map