Vision Longformer for Object Detection

This project provides the source code for the object detection part of vision longformer paper. It is based on detectron2.

Multi-Scale Vision Longformer: A New Vision Transformer for High-Resolution Image Encoding

The classification part of the code and checkpoints can be found here.

Updates

• 03/29/2021: First version of vision longformer paper posted on Arxiv.
  
• 05/17/2021: Performance improved by adding relative positional bias, inspired by Swin Transformer! First version of Object Detection code released.

Usage

Here is an example command for evaluating a pretrained vision-longformer small model on COCO

python -m pip install -e .

ln -s /mnt/data_storage datasets

DETECTRON2_DATASETS=datasets python train_net.py --num-gpus 1 --eval-only --config configs/msvit_maskrcnn_fpn_1x_small_sparse.yaml 
MODEL.TRANSFORMER.MSVIT.ARCH "l1,h3,d96,n1,s1,g1,p4,f7,a0_l2,h3,d192,n2,s1,g1,p2,f7,a0_l3,h6,d384,n8,s1,g1,p2,f7,a0_l4,h12,d768,n1,s1,g0,p2,f7,a0" 
SOLVER.AMP.ENABLED True 
MODEL.WEIGHTS /mnt/model_storage/msvit_det/visionlongformer/vilsmall/maskrcnn1x/model_final.pth

Here is an example training command for training the vision-longformer small model on COCO

python -m pip install -e .

ln -s /mnt/data_storage datasets

# convert the classification checkpoint into a detection checkpoint for initialization
python3 converter.py --source_model "/mnt/model_storage/msvit/visionlongformer/small1281_relative/model_best.pth"
--output_model msvit_pretrain.pth --config configs/msvit_maskrcnn_fpn_3xms_small_sparse.yaml
MODEL.TRANSFORMER.MSVIT.ARCH "l1,h3,d96,n1,s1,g1,p4,f7,a0_l2,h3,d192,n2,s1,g1,p2,f7,a0_l3,h6,d384,n8,s1,g1,p2,f7,a0_l4,h12,d768,n1,s1,g0,p2,f7,a0"

# train with the converted detection checkpoint as initialization
DETECTRON2_DATASETS=datasets python train_net.py --num-gpus 8 --config configs/msvit_maskrcnn_fpn_3xms_small_sparse.yaml
MODEL.WEIGHTS msvit_pretrain.pth MODEL.TRANSFORMER.DROP_PATH 0.2 MODEL.TRANSFORMER.MSVIT.ATTN_TYPE
longformerhand MODEL.TRANSFORMER.MSVIT.ARCH "l1,h3,d96,n1,s1,g1,p4,f7,a0_l2,h3,d192,n2,s1,g1,p2,f7,a0_l3,h6,d384,n8,s1,g1,p2,f7,a0_l4,h12,d768,n1,s1,g0,p2,f7,a0"
SOLVER.AMP.ENABLED True SOLVER.BASE_LR 1e-4 SOLVER.WEIGHT_DECAY 0.1 TEST.EVAL_PERIOD
7330 SOLVER.IMS_PER_BATCH 16

Model Zoo on COCO

Vision Longformer with relative positional bias

Backbone	Method	pretrain	drop_path	Lr Schd	box mAP	mask mAP	#params	FLOPs	checkpoints	log
ViL-Tiny	Mask R-CNN	ImageNet-1K	0.05	1x	41.4	38.1	26.9M	145.6G	ckpt config	log
ViL-Tiny	Mask R-CNN	ImageNet-1K	0.1	3x	44.2	40.6	26.9M	145.6G	ckpt config	log
ViL-Small	Mask R-CNN	ImageNet-1K	0.2	1x	44.9	41.1	45.0M	218.3G	ckpt config	log
ViL-Small	Mask R-CNN	ImageNet-1K	0.2	3x	47.1	42.7	45.0M	218.3G	ckpt config	log
ViL-Medium (D)	Mask R-CNN	ImageNet-21K	0.2	1x	47.6	43.0	60.1M	293.8G	ckpt config	log
ViL-Medium (D)	Mask R-CNN	ImageNet-21K	0.3	3x	48.9	44.2	60.1M	293.8G	ckpt config	log
ViL-Base (D)	Mask R-CNN	ImageNet-21K	0.3	1x	48.6	43.6	76.1M	384.4G	ckpt config	log
ViL-Base (D)	Mask R-CNN	ImageNet-21K	0.3	3x	49.6	44.5	76.1M	384.4G	ckpt config	log
---	---	---	---	---	---	---	---	---
ViL-Tiny	RetinaNet	ImageNet-1K	0.05	1x	40.8	--	16.64M	182.7G	ckpt config	log
ViL-Tiny	RetinaNet	ImageNet-1K	0.1	3x	43.6	--	16.64M	182.7G	ckpt config	log
ViL-Small	RetinaNet	ImageNet-1K	0.1	1x	44.2	--	35.68M	254.8G	ckpt config	log
ViL-Small	RetinaNet	ImageNet-1K	0.2	3x	45.9	--	35.68M	254.8G	ckpt config	log
ViL-Medium (D)	RetinaNet	ImageNet-21K	0.2	1x	46.8	--	50.77M	330.4G	ckpt config	log
ViL-Medium (D)	RetinaNet	ImageNet-21K	0.3	3x	47.9	--	50.77M	330.4G	ckpt config	log
ViL-Base (D)	RetinaNet	ImageNet-21K	0.3	1x	47.8	--	66.74M	420.9G	ckpt config	log
ViL-Base (D)	RetinaNet	ImageNet-21K	0.3	3x	48.6	--	66.74M	420.9G	ckpt config	log

See more fine-grained results in Table 6 and Table 7 in the Vision Longformer paper. We use weight decay 0.05 for all experiments, but search for best drop path in [0.05, 0.1, 0.2, 0.3].

Comparison of various efficient attention mechanims with absolute positional embedding (Small size)

Backbone	Method	pretrain	drop_path	Lr Schd	box mAP	mask mAP	#params	FLOPs	Memory	checkpoints	log
srformer/64	Mask R-CNN	ImageNet-1K	0.1	1x	36.4	34.6	73.3M	224.1G	7.1G	ckpt config	log
srformer/32	Mask R-CNN	ImageNet-1K	0.1	1x	39.9	37.3	51.5M	268.3G	13.6G	ckpt config	log
Partial srformer/32	Mask R-CNN	ImageNet-1K	0.1	1x	42.4	39.0	46.8M	352.1G	22.6G	ckpt config	log
global	Mask R-CNN	ImageNet-1K	0.1	1x	34.8	33.4	45.2M	226.4G	7.6G	ckpt config	log
Partial global	Mask R-CNN	ImageNet-1K	0.1	1x	42.5	39.2	45.1M	326.5G	20.1G	ckpt config	log
performer	Mask R-CNN	ImageNet-1K	0.1	1x	36.1	34.3	45.0M	251.5G	8.4G	ckpt config	log
Partial performer	Mask R-CNN	ImageNet-1K	0.05	1x	42.3	39.1	45.0M	343.7G	20.0G	ckpt config	log
ViL	Mask R-CNN	ImageNet-1K	0.1	1x	42.9	39.6	45.0M	218.3G	7.4G	ckpt config	log
Partial ViL	Mask R-CNN	ImageNet-1K	0.1	1x	43.3	39.8	45.0M	326.8G	19.5G	ckpt config	log

We use weight decay 0.05 for all experiments, but search for best drop path in [0.05, 0.1, 0.2].