Search Multilayer Perceptron-Based Fusion for Efficient and Accurate Siamese Tracking
Organizations: Institute of Mining Artificial Intelligence, Chinese Institute of Coal Science Department of Computer Science, City University of Hong Kong Beijing 100013, China / Hong Kong SAR · Image Processing Center, School of Astronautics, Beihang University Beijing 100191, China · Institute of Mining Artificial Intelligence, Chinese Institute of Coal Science State Key Laboratory of Intelligent Coal Mining and Strata Control Beijing 100013, China
Abstract
Siamese visual trackers have recently advanced through increasingly sophisticated fusion mechanisms built on convolutional or Transformer architectures. However, both struggle to deliver pixel-level interactions efficiently on resource-constrained hardware, leading to a persistent accuracy-efficiency imbalance. Motivated by this limitation, we redesign the Siamese neck with a simple yet effective Multilayer Perception (MLP)-based fusion module that enables pixel-level interaction with minimal structural overhead. Nevertheless, naively stacking MLP blocks introduces a new challenge: computational cost can scale quadratically with channel width. To overcome this, we construct a hierarchical search space of carefully designed MLP modules and introduce a customized relaxation strategy that enables differentiable neural architecture search (DNAS) to decouple channel-width optimization from other architectural choices. This targeted decoupling automatically balances channel width and depth, yielding a low-complexity architecture. The resulting tracker achieves state-of-the-art accuracy-efficiency trade-offs. It ranks among the top performers on four general-purpose and three aerial tracking benchmarks, while maintaining real-time performance on both resource-constrained Graphics Processing Units (GPUs) and Neural Processing Units (NPUs).
Figures & tables
| CH | - | - | ||
| PH | ||||
| CH | - | |||
| PH | ||||
| CH | ||||
| PH |
| Type | Expansion Ratio | Kernel Size | Depthwise |
| k3_t4 | 4 | 3 | ✗ |
| k3_t4_dw | 4 | 3 | ✓ |
| k3_t8 | 8 | 3 | ✗ |
| k3_t8_dw | 8 | 3 | ✓ |
| k5_t4 | 4 | 5 | ✗ |
| k5_t4_dw | 4 | 5 | ✓ |
| Routing Path | Number of Architectures |
| VOT2019 | FPS ↑ | Latency ↓ (ms) | ||||||||
| Orientation | Trackers | Year | Type | EAO↑ | Robustness↓ | OTB 2015 | GOT10K TEST | NFS 30 | ||
| ECO | 2017 | - | - | - | 64.3 | - | 46.6 | - | - | |
| LightTrack(M) | 2021 | cnn | 3 3.3 | 3 2.1 | 65.8 | 61.1 | 56.3 | 50.20 | 19.9 | |
| FEAR(XS) | 2022 | cnn | 25.2 | 56.2 | 66.7 | 6 1.9 | 58.3 | 1 23.33 | 8 .1 | |
| E.T.Track | 2023 | trans | 24.1 | 57.2 | 6 7.8 | 58.3 | 5 9.0 | 48.15 | 20.8 | |
| GPU-constrained platforms | SEAT_LT(ours) | 2023 | mlp | 3 4.0 | 3 1.6 | 6 9.7 | 6 3.6 | 6 1.1 | 8 0.54 | 1 2.4 |
| MACs | Params | FPS | Average Latency | Subgraphs | DDR Latency | UAV20L Accuracy | |
| SEAT_AL( ours ) | 8.13G | 11.47M | 20.41 | 195.47ms | 13 | 892.43ms | 0.593 |
| SiamAPN++ [ 5 ] | 10.25G | 15.15M | 23.57 | 168.64ms | 8 | 624.77ms | 0.533 |
| HiFT [ 36 ] | 4.83G | 9.98M | 4.30 | 921.41ms | 28 | 681.40ms | 0.566 |
| TCTrack [ 37 ] | 3.37G | 7.09M | 0.71 | 5608.77ms | 52 | 3461.16ms | 0.516 |
| SEAT_LT | |||||||||
| Ablation Study | Pre- Fusion | Fusion -Type | Post- Fusion | Fusion -Type | GOT10K (AO)% | OTB2015 (AUC)% | VOT2019 (EAO)% | FPS | Latency (ms) |
| Ab1 | cnn | patch | mlp | pixel | 52.2 | 62.8 | 22.3 | 69.63 | 14.4 |
| Ab2 | transformer | pixel | mlp | pixel | 62.6 | 65.7 | 30.8 | 61.23 | 16.3 |
| Ab0 | mlp | pixel | - | - | 63.5 | 68.1 | 33.7 | 89.39 | 11.2 |
| Ab3 | mlp | pixel | cnn | patch | 63.1 | 69.6 | 31.5 | 83.82 | 11.9 |
| Ab4 | mlp | pixel | transformer | pixel | 6 3.8 | 69.6 | 33.6 | 77.99 | 12.8 |
Appendix figures & tables5 assets
Supplementary material from the paper’s appendix.
Appendix
| Module | Block Type | FLOPs Expression |
| CFM | Convolution-based | |
| Cross-attention-based | ||
| CFM (Ours) | ||
| RFM | Standard CNN (3 3) | |
| Depthwise CNN | ||
| Transformer (4 heads, w/o FFN) |
Visual Object Tracking
Visual object tracking follows objects across video frames, maintaining their locations and identities despite motion, occlusion, and changing appearance.
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