darklabel2.4

• support to save/load data in .csv file
• support MOT data format
• add a new format specifier ("c=n"): it can be used to save/load dummy values (see darklabel.yml for it's usage)
• enhance error handling (make it more robust to various external and internal errors)

darklabel2.3-update2

minor update

• fix possible mismatch between labels and saved images in case of video input
• support to delete labels in intervals
• add two new adjustable parameters in darklabel.yml
  . min_object_size: minimum allowed box size
  . hotkey_return: secondary hotkey for return/enter key (for tracking)
• adjust GUI layout (make it more slim)

darklabel2.3-update1

fix the program to sort image list naturally by their file name.

• before: 0.jpg, 1.jpg, 10.jpg, 100.jpg, 101.jpg, ...
• after: 0.jpg, 1.jpg, 2.jpg, 3.jpg, ...

darklabel2.3-release

Update README.md