9 research outputs found
Cross-stitch Networks for Multi-task Learning
Multi-task learning in Convolutional Networks has displayed remarkable
success in the field of recognition. This success can be largely attributed to
learning shared representations from multiple supervisory tasks. However,
existing multi-task approaches rely on enumerating multiple network
architectures specific to the tasks at hand, that do not generalize. In this
paper, we propose a principled approach to learn shared representations in
ConvNets using multi-task learning. Specifically, we propose a new sharing
unit: "cross-stitch" unit. These units combine the activations from multiple
networks and can be trained end-to-end. A network with cross-stitch units can
learn an optimal combination of shared and task-specific representations. Our
proposed method generalizes across multiple tasks and shows dramatically
improved performance over baseline methods for categories with few training
examples.Comment: To appear in CVPR 2016 (Spotlight
Multi-task CNN Model for Attribute Prediction
This paper proposes a joint multi-task learning algorithm to better predict
attributes in images using deep convolutional neural networks (CNN). We
consider learning binary semantic attributes through a multi-task CNN model,
where each CNN will predict one binary attribute. The multi-task learning
allows CNN models to simultaneously share visual knowledge among different
attribute categories. Each CNN will generate attribute-specific feature
representations, and then we apply multi-task learning on the features to
predict their attributes. In our multi-task framework, we propose a method to
decompose the overall model's parameters into a latent task matrix and
combination matrix. Furthermore, under-sampled classifiers can leverage shared
statistics from other classifiers to improve their performance. Natural
grouping of attributes is applied such that attributes in the same group are
encouraged to share more knowledge. Meanwhile, attributes in different groups
will generally compete with each other, and consequently share less knowledge.
We show the effectiveness of our method on two popular attribute datasets.Comment: 11 pages, 3 figures, ieee transaction pape
Deep Multi-task Multi-label CNN for Effective Facial Attribute Classification
Facial Attribute Classification (FAC) has attracted increasing attention in
computer vision and pattern recognition. However, state-of-the-art FAC methods
perform face detection/alignment and FAC independently. The inherent
dependencies between these tasks are not fully exploited. In addition, most
methods predict all facial attributes using the same CNN network architecture,
which ignores the different learning complexities of facial attributes. To
address the above problems, we propose a novel deep multi-task multi-label CNN,
termed DMM-CNN, for effective FAC. Specifically, DMM-CNN jointly optimizes two
closely-related tasks (i.e., facial landmark detection and FAC) to improve the
performance of FAC by taking advantage of multi-task learning. To deal with the
diverse learning complexities of facial attributes, we divide the attributes
into two groups: objective attributes and subjective attributes. Two different
network architectures are respectively designed to extract features for two
groups of attributes, and a novel dynamic weighting scheme is proposed to
automatically assign the loss weight to each facial attribute during training.
Furthermore, an adaptive thresholding strategy is developed to effectively
alleviate the problem of class imbalance for multi-label learning. Experimental
results on the challenging CelebA and LFWA datasets show the superiority of the
proposed DMM-CNN method compared with several state-of-the-art FAC methods
Deep Learning Architectures for Heterogeneous Face Recognition
Face recognition has been one of the most challenging areas of research in biometrics and computer vision. Many face recognition algorithms are designed to address illumination and pose problems for visible face images. In recent years, there has been significant amount of research in Heterogeneous Face Recognition (HFR). The large modality gap between faces captured in different spectrum as well as lack of training data makes heterogeneous face recognition (HFR) quite a challenging problem. In this work, we present different deep learning frameworks to address the problem of matching non-visible face photos against a gallery of visible faces.
Algorithms for thermal-to-visible face recognition can be categorized as cross-spectrum feature-based methods, or cross-spectrum image synthesis methods. In cross-spectrum feature-based face recognition a thermal probe is matched against a gallery of visible faces corresponding to the real-world scenario, in a feature subspace. The second category synthesizes a visible-like image from a thermal image which can then be used by any commercial visible spectrum face recognition system. These methods also beneficial in the sense that the synthesized visible face image can be directly utilized by existing face recognition systems which operate only on the visible face imagery. Therefore, using this approach one can leverage the existing commercial-off-the-shelf (COTS) and government-off-the-shelf (GOTS) solutions. In addition, the synthesized images can be used by human examiners for different purposes.
There are some informative traits, such as age, gender, ethnicity, race, and hair color, which are not distinctive enough for the sake of recognition, but still can act as complementary information to other primary information, such as face and fingerprint. These traits, which are known as soft biometrics, can improve recognition algorithms while they are much cheaper and faster to acquire. They can be directly used in a unimodal system for some applications. Usually, soft biometric traits have been utilized jointly with hard biometrics (face photo) for different tasks in the sense that they are considered to be available both during the training and testing phases. In our approaches we look at this problem in a different way. We consider the case when soft biometric information does not exist during the testing phase, and our method can predict them directly in a multi-tasking paradigm.
There are situations in which training data might come equipped with additional information that can be modeled as an auxiliary view of the data, and that unfortunately is not available during testing. This is the LUPI scenario. We introduce a novel framework based on deep learning techniques that leverages the auxiliary view to improve the performance of recognition system. We do so by introducing a formulation that is general, in the sense that can be used with any visual classifier.
Every use of auxiliary information has been validated extensively using publicly available benchmark datasets, and several new state-of-the-art accuracy performance values have been set. Examples of application domains include visual object recognition from RGB images and from depth data, handwritten digit recognition, and gesture recognition from video.
We also design a novel aggregation framework which optimizes the landmark locations directly using only one image without requiring any extra prior which leads to robust alignment given arbitrary face deformations. Three different approaches are employed to generate the manipulated faces and two of them perform the manipulation via the adversarial attacks to fool a face recognizer. This step can decouple from our framework and potentially used to enhance other landmark detectors. Aggregation of the manipulated faces in different branches of proposed method leads to robust landmark detection.
Finally we focus on the generative adversarial networks which is a very powerful tool in synthesizing a visible-like images from the non-visible images. The main goal of a generative model is to approximate the true data distribution which is not known. In general, the choice for modeling the density function is challenging. Explicit models have the advantage of explicitly calculating the probability densities. There are two well-known implicit approaches, namely the Generative Adversarial Network (GAN) and Variational AutoEncoder (VAE) which try to model the data distribution implicitly. The VAEs try to maximize the data likelihood lower bound, while a GAN performs a minimax game between two players during its optimization. GANs overlook the explicit data density characteristics which leads to undesirable quantitative evaluations and mode collapse. This causes the generator to create similar looking images with poor diversity of samples. In the last chapter of thesis, we focus to address this issue in GANs framework
Learning to share latent tasks for action recognition
10.1109/ICCV.2013.281Proceedings of the IEEE International Conference on Computer Vision2264-2271PICV