Share Email Print

Proceedings Paper

Object recognition using deep convolutional neural networks with complete transfer and partial frozen layers
Author(s): Maarten C. Kruithof; Henri Bouma; Noëlle M. Fischer; Klamer Schutte
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Object recognition is important to understand the content of video and allow flexible querying in a large number of cameras, especially for security applications. Recent benchmarks show that deep convolutional neural networks are excellent approaches for object recognition. This paper describes an approach of domain transfer, where features learned from a large annotated dataset are transferred to a target domain where less annotated examples are available as is typical for the security and defense domain. Many of these networks trained on natural images appear to learn features similar to Gabor filters and color blobs in the first layer. These first-layer features appear to be generic for many datasets and tasks while the last layer is specific. In this paper, we study the effect of copying all layers and fine-tuning a variable number. We performed an experiment with a Caffe-based network on 1000 ImageNet classes that are randomly divided in two equal subgroups for the transfer from one to the other. We copy all layers and vary the number of layers that is fine-tuned and the size of the target dataset. We performed additional experiments with the Keras platform on CIFAR-10 dataset to validate general applicability. We show with both platforms and both datasets that the accuracy on the target dataset improves when more target data is used. When the target dataset is large, it is beneficial to freeze only a few layers. For a large target dataset, the network without transfer learning performs better than the transfer network, especially if many layers are frozen. When the target dataset is small, it is beneficial to transfer (and freeze) many layers. For a small target dataset, the transfer network boosts generalization and it performs much better than the network without transfer learning. Learning time can be reduced by freezing many layers in a network.

Paper Details

Date Published: 24 October 2016
PDF: 7 pages
Proc. SPIE 9995, Optics and Photonics for Counterterrorism, Crime Fighting, and Defence XII, 99950K (24 October 2016); doi: 10.1117/12.2241177
Show Author Affiliations
Maarten C. Kruithof, TNO (Netherlands)
Henri Bouma, TNO (Netherlands)
Noëlle M. Fischer, TNO (Netherlands)
Klamer Schutte, TNO (Netherlands)

Published in SPIE Proceedings Vol. 9995:
Optics and Photonics for Counterterrorism, Crime Fighting, and Defence XII
Douglas Burgess; Gari Owen; Henri Bouma; Felicity Carlysle-Davies; Robert James Stokes; Yitzhak Yitzhaky, Editor(s)

© SPIE. Terms of Use
Back to Top