  Panoptic Narrative Detection (PND) and Segmentation (PNS) are two challenging
tasks that involve identifying and locating multiple targets in an image
according to a long narrative description. In this paper, we propose a unified
and effective framework called NICE that can jointly learn these two panoptic
narrative recognition tasks. Existing visual grounding tasks use a two-branch
paradigm, but applying this directly to PND and PNS can result in prediction
conflict due to their intrinsic many-to-many alignment property. To address
this, we introduce two cascading modules based on the barycenter of the mask,
which are Coordinate Guided Aggregation (CGA) and Barycenter Driven
Localization (BDL), responsible for segmentation and detection, respectively.
By linking PNS and PND in series with the barycenter of segmentation as the
anchor, our approach naturally aligns the two tasks and allows them to
complement each other for improved performance. Specifically, CGA provides the
barycenter as a reference for detection, reducing BDL's reliance on a large
number of candidate boxes. BDL leverages its excellent properties to
distinguish different instances, which improves the performance of CGA for
segmentation. Extensive experiments demonstrate that NICE surpasses all
existing methods by a large margin, achieving 4.1% for PND and 2.9% for PNS
over the state-of-the-art. These results validate the effectiveness of our
proposed collaborative learning strategy. The project of this work is made
publicly available at https://github.com/Mr-Neko/NICE.
