NExT-Chat: An LMM for Chat, Detection and Segmentation
Authors: name: Ao Zhang, name: Liming Zhao, name: Chen-Wei Xie, name: Yun Zheng, name: Wei Ji, name: Tat-Seng Chua

The development of large language models (LLMs) has greatly advanced the
field of multimodal understanding, leading to the emergence of large multimodal
models (LMMs). In order to enhance the level of visual comprehension, recent
studies have equipped LMMs with region-level understanding capabilities by
representing object bounding box coordinates as a series of text sequences
(pixel2seq). In this paper, we introduce a novel paradigm for object location
modeling called pixel2emb method, where we ask the LMM to output the location
embeddings and then decoded by different decoders. This paradigm allows for
different location formats (such as bounding boxes and masks) to be used in
multimodal conversations Furthermore, this kind of embedding based location
modeling enables the utilization of existing practices in localization tasks,
such as detection and segmentation. In scenarios with limited resources, our
pixel2emb demonstrates superior performance compared to existing
state-of-the-art (SOTA) approaches in both the location input and output tasks
under fair comparison. Leveraging the proposed pixel2emb method, we train an
LMM named NExT-Chat and demonstrate its capability of handling multiple tasks
like visual grounding, region caption, and grounded reasoning.