bathy_threshold_calc.py program takes as input a
single-channel image, for example, band 7 of a WorldView multispectral
image, and computes the threshold separating the water and land
See Section 8.27.3 for further context, and a sample output and graph.
16.4.1. Example usage¶
bathy conda environment as described in
Section 16.4.2 below.
This program can be invoked as:
~/miniconda3/envs/bathy/bin/python $(which bathy_threshold_calc.py) \ --image image.tif --num-samples 1000000
Here it is assumed that ASP’s
bin directory is in the path, otherwise
the full path to this Python script must be specified above.
This tool needs Python 3 and some additional Python packages to be installed with
Conda can be obtained from
on Linux, and the appropriate version on OSX (this script needs to be made executable first). Use the suggested:
directory for installation.
Activate conda. The needed packages can be installed as follows:
conda create --name bathy -c conda-forge python=3.6 gdal conda activate bathy conda install -c conda-forge numpy scipy matplotlib
16.4.3. Command-line options for bathy_threshold_calc.py¶
- -h, --help
Display the help message.
- --image <filename>
The single-channel image to use to find the water-land threshold.
- --num-samples <integer (default: 1000000)>
The number of samples to pick from the image (more samples will result in more accuracy but will be slower).
Do not show the plot.