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HGT-Relief-Map

Presented is a C++ Windows application that creates relief map images from high resolution 1 arc-second HGT files. The application was used to create the relief maps in my New Zealand Digital Elevation Model project.

The application expects a high resolution HGT file ( 1 arc-second ). These files are 3601 by 3601 and contain the height in meters stored as a 16 bit value. The output file is a 1200 by 1200 bitmap/jpg file containing the relief map. Relief maps allow the HGT data to be visualized more easily. For more information about HGT files see my other project.

Using the application

  1. Select an HGT file and press the "Create Relief Bitmap" button. A Bitmap image will be saved to a file with the same name as the HGT file and in the same directory.
  2. Optionally, an additional JPEG can be saved if the "Create additional JPEG" option is selected.
  3. Normal maps can also be created by pressing the "Create Normal Map" button. (I added this feature to help debug my HGT-CUDA project).
  4. To automatically create a Relief/Normal map for each file in the specified directory, select the scan folder option. This saves having to select each file in the directory one at a time.
  5. The cclour scale can be altered using the builtin editor.

Building the application

The project was written using Visual Studio 2019 (make sure the desktop C++ and MFC options are installed).

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Credits

  1. The Vector SIMD code was copied from here.

  2. The colour map was inspired by 3dem application that apparently is no longer supported but an old version can be downloaded from here.

Sample Images

The image below shows a relief map of the Auckland Region S37E174.hgt

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Rotorua S39E176.hgt.

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Wellington/Queen Charlotte Sound S42E174.hgt.

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Otago/Southland S47E169.hgt.

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