LabelImg is now part of the Label Studio community. The popular image annotation tool created by Tzutalin is no longer actively being developed, but you can check out Label Studio, the open source data labeling tool for images, text, hypertext, audio, video and time-series data.
LabelFileFormat: Create a class for LabelFileFormat instead of enum. All file formats should follow the class by specifying extension, reader and writer objects. The file extensions are saved in classes and the detection of file type can be done by loop iterations.
Abstract class for Reader and Writer: Allignment of IO operation for all reader and writers, this makes loading and saving file a static operation, rather than different function by the original design.
Refactor of LabelImg application: