2,057 research outputs found
Zero-Shot Visual Recognition using Semantics-Preserving Adversarial Embedding Networks
We propose a novel framework called Semantics-Preserving Adversarial
Embedding Network (SP-AEN) for zero-shot visual recognition (ZSL), where test
images and their classes are both unseen during training. SP-AEN aims to tackle
the inherent problem --- semantic loss --- in the prevailing family of
embedding-based ZSL, where some semantics would be discarded during training if
they are non-discriminative for training classes, but could become critical for
recognizing test classes. Specifically, SP-AEN prevents the semantic loss by
introducing an independent visual-to-semantic space embedder which disentangles
the semantic space into two subspaces for the two arguably conflicting
objectives: classification and reconstruction. Through adversarial learning of
the two subspaces, SP-AEN can transfer the semantics from the reconstructive
subspace to the discriminative one, accomplishing the improved zero-shot
recognition of unseen classes. Comparing with prior works, SP-AEN can not only
improve classification but also generate photo-realistic images, demonstrating
the effectiveness of semantic preservation. On four popular benchmarks: CUB,
AWA, SUN and aPY, SP-AEN considerably outperforms other state-of-the-art
methods by an absolute performance difference of 12.2\%, 9.3\%, 4.0\%, and
3.6\% in terms of harmonic mean value
Two-Level Adversarial Visual-Semantic Coupling for Generalized Zero-shot Learning
The performance of generative zero-shot methods mainly depends on the quality
of generated features and how well the model facilitates knowledge transfer
between visual and semantic domains. The quality of generated features is a
direct consequence of the ability of the model to capture the several modes of
the underlying data distribution. To address these issues, we propose a new
two-level joint maximization idea to augment the generative network with an
inference network during training which helps our model capture the several
modes of the data and generate features that better represent the underlying
data distribution. This provides strong cross-modal interaction for effective
transfer of knowledge between visual and semantic domains. Furthermore,
existing methods train the zero-shot classifier either on generate synthetic
image features or latent embeddings produced by leveraging representation
learning. In this work, we unify these paradigms into a single model which in
addition to synthesizing image features, also utilizes the representation
learning capabilities of the inference network to provide discriminative
features for the final zero-shot recognition task. We evaluate our approach on
four benchmark datasets i.e. CUB, FLO, AWA1 and AWA2 against several
state-of-the-art methods, and show its performance. We also perform ablation
studies to analyze and understand our method more carefully for the Generalized
Zero-shot Learning task.Comment: Under Submissio
Bidirectional mapping coupled GAN for generalized zero-shot learning
Bidirectional mapping-based generalized zero-shot learning (GZSL) methods rely on the quality of synthesized features to recognize seen and unseen data. Therefore, learning a joint distribution of seen-unseen classes and preserving the distinction between seen-unseen classes is crucial for GZSL methods. However, existing methods only learn the underlying distribution of seen data, although unseen class semantics are available in the GZSL problem setting. Most methods neglect retaining seen-unseen classes distinction and use the learned distribution to recognize seen and unseen data. Consequently, they do not perform well. In this work, we utilize the available unseen class semantics alongside seen class semantics and learn joint distribution through a strong visual-semantic coupling. We propose a bidirectional mapping coupled generative adversarial network (BMCoGAN) by extending the concept of the coupled generative adversarial network into a bidirectional mapping model. We further integrate a Wasserstein generative adversarial optimization to supervise the joint distribution learning. We design a loss optimization for retaining distinctive information of seen-unseen classes in the synthesized features and reducing bias towards seen classes, which pushes synthesized seen features towards real seen features and pulls synthesized unseen features away from real seen features. We evaluate BMCoGAN on benchmark datasets and demonstrate its superior performance against contemporary methods. © 1992-2012 IEEE
Learning Compositional Visual Concepts with Mutual Consistency
Compositionality of semantic concepts in image synthesis and analysis is
appealing as it can help in decomposing known and generatively recomposing
unknown data. For instance, we may learn concepts of changing illumination,
geometry or albedo of a scene, and try to recombine them to generate physically
meaningful, but unseen data for training and testing. In practice however we
often do not have samples from the joint concept space available: We may have
data on illumination change in one data set and on geometric change in another
one without complete overlap. We pose the following question: How can we learn
two or more concepts jointly from different data sets with mutual consistency
where we do not have samples from the full joint space? We present a novel
answer in this paper based on cyclic consistency over multiple concepts,
represented individually by generative adversarial networks (GANs). Our method,
ConceptGAN, can be understood as a drop in for data augmentation to improve
resilience for real world applications. Qualitative and quantitative
evaluations demonstrate its efficacy in generating semantically meaningful
images, as well as one shot face verification as an example application.Comment: 10 pages, 8 figures, 4 tables, CVPR 201
Recent Advances in Transfer Learning for Cross-Dataset Visual Recognition: A Problem-Oriented Perspective
This paper takes a problem-oriented perspective and presents a comprehensive
review of transfer learning methods, both shallow and deep, for cross-dataset
visual recognition. Specifically, it categorises the cross-dataset recognition
into seventeen problems based on a set of carefully chosen data and label
attributes. Such a problem-oriented taxonomy has allowed us to examine how
different transfer learning approaches tackle each problem and how well each
problem has been researched to date. The comprehensive problem-oriented review
of the advances in transfer learning with respect to the problem has not only
revealed the challenges in transfer learning for visual recognition, but also
the problems (e.g. eight of the seventeen problems) that have been scarcely
studied. This survey not only presents an up-to-date technical review for
researchers, but also a systematic approach and a reference for a machine
learning practitioner to categorise a real problem and to look up for a
possible solution accordingly
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