Euclid is a tool for manual labelling of data - sets, such as those found in Deep learning systems that employ Caffe. This includes systems like DIGITS, and YOLO. It is an object / class labelling tool for machine learning frameworks.
This tool runs on Linux and Windows, and is based on Python 2.7/Tkinter. Though the UI is a bit clunky it is functional at this point.
Label format support:
The tool supports Kitti data-set output format, and YOLO output format at this time.
For the actual format, see the below link, or the Kitti dataset development kit.
See also, SLOTH, for variety of xml format support,
And also, for PASCAL dataset,
Euclid now referred in DIGITS pages: