67,756 research outputs found
A practical two-stage training strategy for multi-stream end-to-end speech recognition
The multi-stream paradigm of audio processing, in which several sources are
simultaneously considered, has been an active research area for information
fusion. Our previous study offered a promising direction within end-to-end
automatic speech recognition, where parallel encoders aim to capture diverse
information followed by a stream-level fusion based on attention mechanisms to
combine the different views. However, with an increasing number of streams
resulting in an increasing number of encoders, the previous approach could
require substantial memory and massive amounts of parallel data for joint
training. In this work, we propose a practical two-stage training scheme.
Stage-1 is to train a Universal Feature Extractor (UFE), where encoder outputs
are produced from a single-stream model trained with all data. Stage-2
formulates a multi-stream scheme intending to solely train the attention fusion
module using the UFE features and pretrained components from Stage-1.
Experiments have been conducted on two datasets, DIRHA and AMI, as a
multi-stream scenario. Compared with our previous method, this strategy
achieves relative word error rate reductions of 8.2--32.4%, while consistently
outperforming several conventional combination methods.Comment: submitted to ICASSP 201
FaceFilter: Audio-visual speech separation using still images
The objective of this paper is to separate a target speaker's speech from a
mixture of two speakers using a deep audio-visual speech separation network.
Unlike previous works that used lip movement on video clips or pre-enrolled
speaker information as an auxiliary conditional feature, we use a single face
image of the target speaker. In this task, the conditional feature is obtained
from facial appearance in cross-modal biometric task, where audio and visual
identity representations are shared in latent space. Learnt identities from
facial images enforce the network to isolate matched speakers and extract the
voices from mixed speech. It solves the permutation problem caused by swapped
channel outputs, frequently occurred in speech separation tasks. The proposed
method is far more practical than video-based speech separation since user
profile images are readily available on many platforms. Also, unlike
speaker-aware separation methods, it is applicable on separation with unseen
speakers who have never been enrolled before. We show strong qualitative and
quantitative results on challenging real-world examples.Comment: Under submission as a conference paper. Video examples:
https://youtu.be/ku9xoLh62
Fine-graind Image Classification via Combining Vision and Language
Fine-grained image classification is a challenging task due to the large
intra-class variance and small inter-class variance, aiming at recognizing
hundreds of sub-categories belonging to the same basic-level category. Most
existing fine-grained image classification methods generally learn part
detection models to obtain the semantic parts for better classification
accuracy. Despite achieving promising results, these methods mainly have two
limitations: (1) not all the parts which obtained through the part detection
models are beneficial and indispensable for classification, and (2)
fine-grained image classification requires more detailed visual descriptions
which could not be provided by the part locations or attribute annotations. For
addressing the above two limitations, this paper proposes the two-stream model
combining vision and language (CVL) for learning latent semantic
representations. The vision stream learns deep representations from the
original visual information via deep convolutional neural network. The language
stream utilizes the natural language descriptions which could point out the
discriminative parts or characteristics for each image, and provides a flexible
and compact way of encoding the salient visual aspects for distinguishing
sub-categories. Since the two streams are complementary, combining the two
streams can further achieves better classification accuracy. Comparing with 12
state-of-the-art methods on the widely used CUB-200-2011 dataset for
fine-grained image classification, the experimental results demonstrate our CVL
approach achieves the best performance.Comment: 9 pages, to appear in CVPR 201
ModDrop: adaptive multi-modal gesture recognition
We present a method for gesture detection and localisation based on
multi-scale and multi-modal deep learning. Each visual modality captures
spatial information at a particular spatial scale (such as motion of the upper
body or a hand), and the whole system operates at three temporal scales. Key to
our technique is a training strategy which exploits: i) careful initialization
of individual modalities; and ii) gradual fusion involving random dropping of
separate channels (dubbed ModDrop) for learning cross-modality correlations
while preserving uniqueness of each modality-specific representation. We
present experiments on the ChaLearn 2014 Looking at People Challenge gesture
recognition track, in which we placed first out of 17 teams. Fusing multiple
modalities at several spatial and temporal scales leads to a significant
increase in recognition rates, allowing the model to compensate for errors of
the individual classifiers as well as noise in the separate channels.
Futhermore, the proposed ModDrop training technique ensures robustness of the
classifier to missing signals in one or several channels to produce meaningful
predictions from any number of available modalities. In addition, we
demonstrate the applicability of the proposed fusion scheme to modalities of
arbitrary nature by experiments on the same dataset augmented with audio.Comment: 14 pages, 7 figure
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