0.3.1

Changes since last release

• Implement DenseNet, VGG backbones.
• Add option to freeze backbone layers.
• Add logging of evaluation to tensorboard.
• Add pretty colors for 80 classes.
• Fix batch_size > 1 issues.
• Refactor model outputs (should hopefully stay like this now).
• Simplified training by splitting into "training model" and "inference model".
• Add structure for backbone specific functions (such as load_model).
• Encode regression as x1/y1/x2/y2 offsets (increases mAP to 0.350, previously 0.345).
• Use nearest upsampling method.

Credits to:
@vidosits
@cgratie
@DiegoAgher
@eduramiba
@GuillaumeErhard
@Muhannes
@hgaiser
@iver56
@jjiunlin
@srslynow
@de-vri-es
@Ori226
@pedroconceicao
@pderian
@rodrigo2019
@lvaleriu
@yhenon