Understanding when spatial transformer networks do not support invariance, and what to do about it

Autor: Lukas Finnveden, Tony Lindeberg, Ylva Jansson
Jazyk: angličtina
Rok vydání: 2021
Předmět:
FOS: Computer and information sciences
Network complexity
Computer science
Computer Vision and Pattern Recognition (cs.CV)
Computer Science - Computer Vision and Pattern Recognition
spatial transformer networks
02 engineering and technology
invariant neural networks
010501 environmental sciences
01 natural sciences
Convolutional neural network
Datorseende och robotik (autonoma system)
convolutional neural networks
0202 electrical engineering
electronic engineering
information engineering

Practical implications
Computer Vision and Robotics (Autonomous Systems)
0105 earth and related environmental sciences
Transformer (machine learning model)
business.industry
deep learning
Pattern recognition
Spatial transformation
Image alignment
020201 artificial intelligence & image processing
Artificial intelligence
business
Zdroj: ICPR
Popis: Spatial transformer networks (STNs) were designed to enable convolutional neural networks (CNNs) to learn invariance to image transformations. STNs were originally proposed to transform CNN feature maps as well as input images. This enables the use of more complex features when predicting transformation parameters. However, since STNs perform a purely spatial transformation, they do not, in the general case, have the ability to align the feature maps of a transformed image with those of its original. STNs are therefore unable to support invariance when transforming CNN feature maps. We present a simple proof for this and study the practical implications, showing that this inability is coupled with decreased classification accuracy. We therefore investigate alternative STN architectures that make use of complex features. We find that while deeper localization networks are difficult to train, localization networks that share parameters with the classification network remain stable as they grow deeper, which allows for higher classification accuracy on difficult datasets. Finally, we explore the interaction between localization network complexity and iterative image alignment.
Comment: 13 pages, 7 figures, 6 tables
Databáze: OpenAIRE