2,019 research outputs found
A random forest approach to segmenting and classifying gestures
This thesis investigates a gesture segmentation and recognition scheme that employs a random forest classification model. A complete gesture recognition system should localize and classify each gesture from a given gesture vocabulary, within a continuous video stream. Thus, the system must determine the start and end points of each gesture in time, as well as accurately recognize the class label of each gesture. We propose a unified approach that performs the tasks of temporal segmentation and classification simultaneously. Our method trains a random forest classification model to recognize gestures from a given vocabulary, as presented in a training dataset of video plus 3D body joint locations, as well as out-of-vocabulary (non-gesture) instances. Given an input video stream, our trained model is applied to candidate gestures using sliding windows at multiple temporal scales. The class label with the highest classifier confidence is selected, and its corresponding scale is used to determine the segmentation boundaries in time. We evaluated our formulation in segmenting and recognizing gestures from two different benchmark datasets: the NATOPS dataset of 9,600 gesture instances from a vocabulary of 24 aircraft handling signals, and the CHALEARN dataset of 7,754 gesture instances from a vocabulary of 20 Italian communication gestures. The performance of our method compares favorably with state-of-the-art methods that employ Hidden Markov Models or Hidden Conditional Random Fields on the NATOPS dataset. We conclude with a discussion of the advantages of using our model
Deep Learning-Based Action Recognition
The classification of human action or behavior patterns is very important for analyzing situations in the field and maintaining social safety. This book focuses on recent research findings on recognizing human action patterns. Technology for the recognition of human action pattern includes the processing technology of human behavior data for learning, technology of expressing feature values ​​of images, technology of extracting spatiotemporal information of images, technology of recognizing human posture, and technology of gesture recognition. Research on these technologies has recently been conducted using general deep learning network modeling of artificial intelligence technology, and excellent research results have been included in this edition
Computational Models for the Automatic Learning and Recognition of Irish Sign Language
This thesis presents a framework for the automatic recognition of Sign Language
sentences. In previous sign language recognition works, the issues of;
user independent recognition, movement epenthesis modeling and automatic
or weakly supervised training have not been fully addressed in a single recognition
framework. This work presents three main contributions in order to
address these issues.
The first contribution is a technique for user independent hand posture
recognition. We present a novel eigenspace Size Function feature which is
implemented to perform user independent recognition of sign language hand
postures.
The second contribution is a framework for the classification and spotting
of spatiotemporal gestures which appear in sign language. We propose a
Gesture Threshold Hidden Markov Model (GT-HMM) to classify gestures
and to identify movement epenthesis without the need for explicit epenthesis
training.
The third contribution is a framework to train the hand posture and spatiotemporal
models using only the weak supervision of sign language videos
and their corresponding text translations. This is achieved through our proposed
Multiple Instance Learning Density Matrix algorithm which automatically
extracts isolated signs from full sentences using the weak and noisy
supervision of text translations. The automatically extracted isolated samples
are then utilised to train our spatiotemporal gesture and hand posture
classifiers.
The work we present in this thesis is an important and significant contribution
to the area of natural sign language recognition as we propose a
robust framework for training a recognition system without the need for
manual labeling
SDFE-LV: A Large-Scale, Multi-Source, and Unconstrained Database for Spotting Dynamic Facial Expressions in Long Videos
In this paper, we present a large-scale, multi-source, and unconstrained
database called SDFE-LV for spotting the onset and offset frames of a complete
dynamic facial expression from long videos, which is known as the topic of
dynamic facial expression spotting (DFES) and a vital prior step for lots of
facial expression analysis tasks. Specifically, SDFE-LV consists of 1,191 long
videos, each of which contains one or more complete dynamic facial expressions.
Moreover, each complete dynamic facial expression in its corresponding long
video was independently labeled for five times by 10 well-trained annotators.
To the best of our knowledge, SDFE-LV is the first unconstrained large-scale
database for the DFES task whose long videos are collected from multiple
real-world/closely real-world media sources, e.g., TV interviews,
documentaries, movies, and we-media short videos. Therefore, DFES tasks on
SDFE-LV database will encounter numerous difficulties in practice such as head
posture changes, occlusions, and illumination. We also provided a comprehensive
benchmark evaluation from different angles by using lots of recent
state-of-the-art deep spotting methods and hence researchers interested in DFES
can quickly and easily get started. Finally, with the deep discussions on the
experimental evaluation results, we attempt to point out several meaningful
directions to deal with DFES tasks and hope that DFES can be better advanced in
the future. In addition, SDFE-LV will be freely released for academic use only
as soon as possible
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