  We present a strong object detector with encoder-decoder pretraining and
finetuning. Our method, called Group DETR v2, is built upon a vision
transformer encoder ViT-Huge~\cite{dosovitskiy2020image}, a DETR variant
DINO~\cite{zhang2022dino}, and an efficient DETR training method Group
DETR~\cite{chen2022group}. The training process consists of self-supervised
pretraining and finetuning a ViT-Huge encoder on ImageNet-1K, pretraining the
detector on Object365, and finally finetuning it on COCO. Group DETR v2
achieves $\textbf{64.5}$ mAP on COCO test-dev, and establishes a new SoTA on
the COCO leaderboard https://paperswithcode.com/sota/object-detection-on-coco
