PyTorch implementation of:

• SSD: Single Shot Multibox Detector
• SSD-Lite: Lightweight SSD based on MobileNet
• RetinaNet: Focal Loss for Dense Object Detection

Evaluation Results on VOC2007 test dataset

model	augumentation	training set	epochs	loss	mAP	checkpoint
ssd300	X	VOC2007 trainval	200	0.081	0.430
ssd300	X	VOC2007/2012 trainval	200	0.081	0.522
ssdlite	O	VOC2007/2012 trainval	200	2.469	0.712	download
ssd300	O	VOC2007/2012 trainval	200	2.139	0.776	download
ssd512	O	VOC2007/2012 trainval	200	2.012	0.792	download

option used for training is --use_multi_step_lr

Status

• Implement SSD / SSDLite model
• Train SSD / SSDLite and add evaluation results
• Implement RetinaNet
• Train RetinaNet with Focal Loss and add evaluataion result
• Implement EfficientDet
• Train EfficientDet and add evaluation result
• Support COCO dataset
• Support custom dataset
• Implement VGG challenge's mAP calculator
• Implement COCO challenge's mAP calculator

Pre-requisite

pip install -r requirements.txt

Train

train with default parameter (dataset will be downloaded automatically)

python detect_train.py

Command Arguments

name	description	default
--model	model name	ssd300
--dataset	dataset name	VOC
--dataset_root	dataset location	downloads
--download	download dataset	False
--epochs	number of epochs to run	200
--batch_size	size of mini-batch	32
--lr	learning rate for SGD	1e-3
--weight_decay	weight decay for SGD	5e-4
--gamma	gamma for lr scheduler	0.1
--th_conf	confidence threshold	0.5
--th_iou	iou threshold	0.5
--resume	resume training	None
--use_step_lr	use step lr scheduler	False
--step_size	step_size for step lr scheduler	30
--use_multi_step_lr	use multi step lr scheduler	False
--use_plateau_lr	use plateau lr scheduler	False
--milestones	milestones for multi step lr scheduler	140 170
--disable_augmentation	disable random augmentation	False
--enable_letterbox	enable letter boxing image	False

note: in case of ssd300 model, 11GB GPU memory is required for batch_size 32 and 8GB GPU memory is required for batch_size 28

Available models

name	description
ssd300	alias of ssd300-voc
ssd300-voc	SSD with input size 300x300 and num_class=20
ssd300-bn-voc	batch normalization adopted version of ssd300-voc
ssd512	alias of ssd512-voc
ssd512-voc	SSD with input size 512x512 and num_class=20
ssdlite	alias of ssdlite-mobilenetv2-voc
ssdlite-mobilenetv2-voc	SSD with MobileNet v2 backbone, input size 320x320 and num_class=20
retinanet	alias of retinanet-50-500-voc
retinanet-50-500-voc	RetinaNet with resenet-50 backbone, input size 500x500 and num_class=20
retinanet-101-500-voc	RetinaNet with resenet-101 backbone, input size 500x500 and num_class=20
retinanet-50-600-voc	RetinaNet with resenet-50 backbone, input size 600x600 and num_class=20
retinanet-101-600-voc	RetinaNet with resenet-101 backbone, input size 600x600 and num_class=20

Available datasets

name	description
VOC	VOC dataset (2007+2012)
VOC2007	VOC dataset (2007 only)
VOC2012	VOC dataset (2012 only)

Example

Training SSD with multi step lr and batch_size is 32 (default)

python detect_train.py --use_multi_step_lr

Training SSD-Lite with multi step lr and batch_size 25 (SSD-Lite model is not tested yet)

python detect_train.py --model ssdlite --use_multi_step_lr --milestones 140 160 --batch_size 25

Resume training

python detect_train.py --resume checkpoints/ssdlite_latest.pth

Evaluation

calculate mAP with test image set

python detect_eval.py

Command Arguments

name	description	default
--model	model name	ssd300
--dataset	dataset name	VOC
--dataset_root	dataset location	downloads
--weight	weight file name	checkpoints/{MODEL_NAME}_latest.pth
--enable_letterbox	enable letter boxing image	False

Single run

python detect_single.py image1 [image2] [image3] [...]

Command Arguments

name	description	default
--model	model name	ssd300
--weight	weight file name	checkpoints/{MODEL_NAME}_latest.pth
--th_conf	confidence threshold	0.5
--th_iou	iou threshold	0.5
--enable_letterbox	enable letter boxing image	False
--outfile	save result to file	None