Sim-to-Real Generalization of Computer Vision with Domain Adaptation, Style Randomization, and Multi-Task Learning
Name
Hannes Liik
Abstract
In recent years, supervised deep learning has been very successful in computer vision applications. This success comes at the cost of a large amount of labeled data required to train artificial neural networks. However, manual labeling can be very expensive. Semantic segmentation, the task of pixel-wise classification of images, requires painstaking pixel-level annotation. The particular difficulty of manual labeling for semantic segmentation motivates research into alternatives. One solution is to use simulations, which can generate semantic segmentation ground truth automatically. Unfortunately, in practice, simulation-trained models have been shown to generalize poorly to the real world.
This work considers a simulation environment, used to train models for semantic segmentation, and real-world environments to evaluate their generalization. Three different approaches are studied to improve generalization from simulation to reality. Firstly, using a generative image-to-image model to make the simulation look realistic. Secondly, using style randomization, a form of data augmentation using style transfer, to make the model more robust to change in visual style. Thirdly, using depth estimation as an auxiliary task to enable learning of geometry.% Finally, the methods are combined to study their complementarity.
Our results show that the first method, image-to-image translation, improves performance on environments similar to the simulation. By applying style randomization, the trained models generalized better to completely new environments. The additional depth estimation task did not improve performance, except by a small amount when combined with style randomization.
This work considers a simulation environment, used to train models for semantic segmentation, and real-world environments to evaluate their generalization. Three different approaches are studied to improve generalization from simulation to reality. Firstly, using a generative image-to-image model to make the simulation look realistic. Secondly, using style randomization, a form of data augmentation using style transfer, to make the model more robust to change in visual style. Thirdly, using depth estimation as an auxiliary task to enable learning of geometry.% Finally, the methods are combined to study their complementarity.
Our results show that the first method, image-to-image translation, improves performance on environments similar to the simulation. By applying style randomization, the trained models generalized better to completely new environments. The additional depth estimation task did not improve performance, except by a small amount when combined with style randomization.
Graduation Thesis language
English
Graduation Thesis type
Master - Computer Science
Supervisor(s)
Tambet Matiisen
Defence year
2020