Pyshepseg Release Notes¶

Version 2.0.0 (2023-01-04)¶

New Features:

A test script (pyshepseg_runtests) that can be run to confirm the install is working as intended.
Split up the parts of doTiledSegmentation() so they can be run in parallel.
Check syntax with flake8 and run test script on new PRs in github.
Use entry points for the command line scripts rather than creating our own. Should make running on Windows easier.
Added ability to calculate “spatial” statistics on the segments.
Use numpydoc for creating Sphinx documentation.
Subset functionality is now in a separate “subset” module.
Statistics functionality now in a new “tilingstats” module.

Bug Fixes:

Guard against Float images being used for calculating statistics as the results were undefined.
Added other checks to ensure that the image having statistics calculated matches spatially with the segmented image.
Add the ability to add GDAL driver creation options for the output image of a segmentation.
Create the histogram column as a Real to match common GDAL usage.
Add checks to ensure histogram and colour columns aren’t created if they already exist.
Ensure the first segment of each RAT Page isn’t initally set to ‘complete’ before use.
Raise error if any incomplete RAT Pages are found during processing as this indicates the RAT contains more entries than unique values in the image.
When calculating statistics, open the file that the stats are calculated on in read only mode so /vsi filesystems can be used.
Increase default overlap for tiled segmentation as the old value could result in inconsistencies and segments that were missing from the image (but in the RAT).
Remove dependency on distutils which is now deprecated.

New Features:

New Sphinx documentation located at https://www.pyshepseg.org.
Added a new subsetImage() function to the tiling module that subsets an already segemented image and collapses the RAT so there are no redundant entries. Also added a test_pyshepseg_subset.py command line program to test this functionality.
Exclude any nodata pixels values during statistics calculation.

New Features:

Added pyshsep.tiling module to allow processing of large rasters in a memory-efficient manner.
Added pyshepseg.tiling.calcPerSegmentStatsTiled() function to enable calculation of per-segment statistics in a fast and memory-efficient manner.
Added pyshepseg.utils.writeColorTableFromRatColumns() function, to add colour table calculated from per-segment statistics

Initial implementation of segmentation algorithm. Other facilities will be added as we get to them.