March 21, 2023

What’s New in Global Mapper SDK v24.1?

Written by: Amanda Lind


Version 24.1 of the SDK has been updated to include many of the new features found in the updated Standard and Pro desktop versions. The Global Mapper Software Developer Toolkit (SDK), also known as an API, gives developers the ability to work with the Global Mapper SDK to develop custom applications. The SDK allows much of the functionality of Global Mapper to be used within your own applications. It is a standard Windows DLL and can be used with many programming languages on a Windows platform, including Visual C++, C#, and Python. Here are some of the new features in version 24.1. 


This ease of use function allows you to search for layers by name. Available in both the Standard and Pro versions, the GM_FindLoadedLayer function takes a string argument, and searches for any layers with a matching description attribute, and returns that layer’s 32-bit handle. Since all other functions in Global Mapper use handles to identify a layer, GM_FindLoadedLayer is a very helpful function that makes it easier to work with layers and construct workflows in the Global Mapper SDK. 

Convolution filters

Don’t be convoluted by the title; these filters for raster data are straightforward. The standard version Global Mapper SDK 24.1 has the ability to apply a filter to an existing layer. This new Pro function lets users create new layers with the filters. The Apply Convolution Filter function takes any single raster layer (image or terrain) and applies a filter that can be used to sharpen, blur, enhance, or help detect edges. 

Convolution filters work by using a weighted kernel (3×3, 5×5, etc.), to recalculate a pixel’s values based on the pixels around it. In the image below, compare examples of Horizontal and Vertical Sobel filters. The Kernels are described as a grid matrix, where the cell being calculated is located in the center. A pattern of weighted values, and zeros to ignore certain values, in the kernel helps to emphasize patterns depending on what cells are emphasized and by how much. 

Swipe to compare examples of Horizontal and Vertical Sobel filters. The two images are of the same location and compare an elevation raster (left) and an image (right).

Contours from lidar

Before this update, contour lines could only be generated from a solid surface elevation raster such as a digital elevation model (DEM). If you are looking to create contours from lidar data, this required the extra step of manually creating a grid/DEM before using the Contours function. This new update, available in the Pro version only, allows the user to generate contour lines directly from lidar data. How does this work? Under the hood, Global Mapper will automatically generate a temporary DEM to pull the contours from. As always, you’ll want to be sure that your points are suitably classified and filtered before creating the contours as you won’t be able to see the parent DEM layer.

Contours generated from lidar data containing vegetation and buildings.
Contours generated from lidar data.

The Global Mapper Software Developer Toolkit contains extensive import and export file compatibility to ensure that it is one of the most interoperable GIS applications available today in the market. To download a trial of the Global Mapper SDK, visit the Blue Marble Geographics website For any questions or to request a trial of the Global Mapper Pro SDK, please contact

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