  Open World Object Detection (OWOD) is a novel and challenging computer vision
task that enables object detection with the ability to detect unknown objects.
Existing methods typically estimate the object likelihood with an additional
objectness branch, but ignore the conflict in learning objectness and
classification boundaries, which oppose each other on the semantic manifold and
training objective. To address this issue, we propose a simple yet effective
learning strategy, namely Decoupled Objectness Learning (DOL), which divides
the learning of these two boundaries into suitable decoder layers. Moreover,
detecting unknown objects comprehensively requires a large amount of
annotations, but labeling all unknown objects is both difficult and expensive.
Therefore, we propose to take advantage of the recent Large Vision Model (LVM),
specifically the Segment Anything Model (SAM), to enhance the detection of
unknown objects. Nevertheless, the output results of SAM contain noise,
including backgrounds and fragments, so we introduce an Auxiliary Supervision
Framework (ASF) that uses a pseudo-labeling and a soft-weighting strategies to
alleviate the negative impact of noise. Extensive experiments on popular
benchmarks, including Pascal VOC and MS COCO, demonstrate the effectiveness of
our approach. Our proposed Unknown Sensitive Detector (USD) outperforms the
recent state-of-the-art methods in terms of Unknown Recall, achieving
significant improvements of 14.3\%, 15.5\%, and 8.9\% on the M-OWODB, and
27.1\%, 29.1\%, and 25.1\% on the S-OWODB.
