NeuFlow: Real-time, High-accuracy Optical Flow Estimation on Robots Using Edge Devices (2403.10425v1)

Abstract: Real-time high-accuracy optical flow estimation is a crucial component in various applications, including localization and mapping in robotics, object tracking, and activity recognition in computer vision. While recent learning-based optical flow methods have achieved high accuracy, they often come with heavy computation costs. In this paper, we propose a highly efficient optical flow architecture, called NeuFlow, that addresses both high accuracy and computational cost concerns. The architecture follows a global-to-local scheme. Given the features of the input images extracted at different spatial resolutions, global matching is employed to estimate an initial optical flow on the 1/16 resolution, capturing large displacement, which is then refined on the 1/8 resolution with lightweight CNN layers for better accuracy. We evaluate our approach on Jetson Orin Nano and RTX 2080 to demonstrate efficiency improvements across different computing platforms. We achieve a notable 10x-80x speedup compared to several state-of-the-art methods, while maintaining comparable accuracy. Our approach achieves around 30 FPS on edge computing platforms, which represents a significant breakthrough in deploying complex computer vision tasks such as SLAM on small robots like drones. The full training and evaluation code is available at https://github.com/neufieldrobotics/NeuFlow.

• The paper introduces NeuFlow with a global-to-local optical flow framework that balances real-time performance and high accuracy.
• NeuFlow employs hierarchical feature extraction using cross-attention and local refinement, achieving a 10×–80× speedup over leading methods.
• The method supports critical robotics applications like SLAM, object tracking, and visual odometry on resource-constrained edge devices.

NeuFlow: Achieving Efficient Real-Time Optical Flow on Edge Devices

The paper "NeuFlow: Real-time, High-accuracy Optical Flow Estimation on Robots Using Edge Devices" introduces an innovative optical flow architecture designed to operate efficiently on edge computing platforms. The authors focus on optimizing the balance between computational load and accuracy to support applications such as SLAM, object tracking, and visual odometry in robotics. Herein, I provide a structured overview of the methods, results, and implications presented in this research.

Architectural Design

NeuFlow is constructed upon a global-to-local optical flow estimation framework. It leverages a hierarchical image feature extraction strategy combining shallow CNN backbones and operations at different scales of resolution. The essence of NeuFlow is to initially perform a global cross-attention at a coarse resolution (1/16) to handle large displacements effectively. This is followed by a self-attention mechanism for resolving ambiguities, and a subsequent local refinement at a finer resolution (1/8) using convolutional layers. The architecture culminates with a convex upsampling process to achieve full-resolution optical flow.

Performance Analysis

The evaluation of NeuFlow shows a significant computational advantage over prominent optical flow methods including RAFT, GMA, GMFlow, and FlowFormer. Empirical results demonstrate that NeuFlow achieves a speedup ranging from 10× to 80× compared to these state-of-the-art methods, while maintaining comparable accuracy. For instance, NeuFlow achieves around 30 FPS on a Jetson Orin Nano for typical image sizes (e.g., 512×384), underscoring its practicality for real-time robotic applications.

Across the FlyingThings and Sintel datasets, NeuFlow provides results comparable to the latest techniques but with significantly reduced computational times, thereby underscoring its efficiency, especially in large displacement scenarios. The comparisons favor NeuFlow as a superior choice when both speed and accuracy are critical, particularly on resource-constrained platforms like the Jetson Orin Nano.

Implications and Future Directions

The contributions of NeuFlow substantiate a key advancement towards deploying optical flow algorithms on edge devices. This research opens the door for small robotic systems, such as drones, to employ sophisticated visual processing algorithms hitherto constrained to more powerful hardware setups. The open-source release of NeuFlow further encourages community involvement in expanding its use and exploring new applications.

Future work can explore several avenues, including enhancing accuracy through iterative refinement or expanding the architecture’s capacity (e.g., deeper feature extraction networks, more cross-attention layers). On the efficiency front, there is potential to incorporate lightweight network models like MobileNets or utilize pruning and quantization techniques for further optimization. Such developments could broaden NeuFlow's applicability, potentially transforming efficiencies in real-time perception tasks on edge computing devices.

In conclusion, NeuFlow occupies a pivotal space by addressing the trade-off between computational efficiency and optical flow accuracy. This work not only enriches the optical flow estimation domain but also propels practical implementations in the robotics and computer vision fields, emphasizing both academic and industrial growth opportunities.