ECO-Net.
Accepted at NeurIPS 2026

ECO-Net

Multi-Part Object Representations via Graph Structures and Co-Part Discovery

Alex Foo, Wynne Hsu, and Mong-Li Lee

School of Computing, National University of Singapore

Discovering multi-part objects through explicit graphs,
co-part discovery, and part-centric regularization.

Recognizing the whole, even when parts are hidden.

Implicit part–whole representations can fail under occlusion and distribution shifts. ECO-Net makes part features and spatial relationships explicit, then discovers objects from recurring co-part structure.

Introduction and motivation: comparison of multi-part object representations

Object-centric representations that capture part–whole structure.

Discovering object-centric representations from images can significantly enhance the robustness, sample efficiency and generalizability of vision models. Works on images with multi-part objects typically follow an implicit object representation approach, which fails to recognize these learned objects in occluded or out-of-distribution contexts. This is due to the assumption that object part-whole relations are implicitly encoded into the representations through indirect training objectives. We address this limitation by proposing a novel method that uses explicit graph representations for parts and introduces a new co-part algorithm for multi-part object discovery. The part representations are refined with a part-centric regularization objective. We then introduce three benchmarks to evaluate the robustness of object-centric methods in recognizing multi-part objects within occluded and out-of-distribution settings. Experimental results on simulated, realistic, and real-world images show marked improvements in the quality of discovered objects compared to state-of-the-art methods, as well as the accurate recognition of multi-part objects in occluded and out-of-distribution contexts. We also show that the discovered object-centric representations can more accurately predict key multi-part object properties in a downstream task, highlighting the potential of our method to advance the field of object-centric representations.

01

Explicit graphs

Represent part features as nodes and spatial relationships as edges.

02

Co-part discovery

Group recurring parts with similar spatial relationships into objects.

03

Robustness evaluation

Evaluate multi-part object recognition under occlusion and out-of-distribution conditions.

From parts to structured objects.

Overview of our proposed ECO-Net.
Overview of our proposed ECO-Net.
Overview of object discovery. (a) Each node in the graph summarizes the position-invariant features (shape, texture, distilled) of each part, while each edge depicts the spatial relationships between parts. (b) Repeated occurrence of similar parts with similar spatial relationships are grouped into objects. (c) We maximize the semantic similarity between all parts which belong to the same object across images and simultaneously minimize the semantic similarity between all other parts.
Overview of object discovery. (a) Each node in the graph summarizes the position-invariant features (shape, texture, distilled) of each part, while each edge depicts the spatial relationships between parts. (b) Repeated occurrence of similar parts with similar spatial relationships are grouped into objects. (c) We maximize the semantic similarity between all parts which belong to the same object across images and simultaneously minimize the semantic similarity between all other parts.

Watch the discovery process.

Visualization of Co-Part Object Discovery Algorithm on Tetrominoes and AbsScene samples.

Tetrominoes

Visualization of Co-Part Object Discovery Algorithm.
Download original MOV ↗

AbsScene

Visualization of Co-Part Object Discovery Algorithm.
Download original MOV ↗

Discovering objects. Recognizing their structure.

Evaluation on simulated, realistic, and real-world images, including occluded and out-of-distribution settings.

Foreground object discovery

Evaluation scores of discovered foreground objects.
Evaluation scores of discovered foreground objects.
Visualization of discovered objects.
Visualization of discovered objects.

Occlusion and generalization

Occlusion and generalization results with captions embedded in the figure
Visualization of discovered objects with occlusion.
Visualization of discovered objects with occlusion.
Visualization of discovered objects with occlusion.
Visualization of discovered objects with occlusion.

Out-of-distribution recognition

Visualization of discovered objects on out-of-distribution test set AbsScene-C.
Visualization of discovered objects on out-of-distribution test set AbsScene-C.

Cite this work.

@inproceedings{foo2026multipart,
  title     = {Multi-Part Object Representations via Graph Structures and Co-Part Discovery},
  author    = {Foo, Alex and Hsu, Wynne and Lee, Mong-Li},
  booktitle = {Advances in Neural Information Processing Systems},
  year      = {2026}
}