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Real-time analysis of surveillance video data
Big
data continues to grow exponentially, and surveillance video has become
one of the largest sources. The surveillance-video data acquired by
existing large networks of surveillance cameras introduce many
technological challenges, including storage, transmission, and
analysis. Among these, one of the most critical challenges is how to
intelligently analyze and understand the visual information, e.g., for
automatic video surveillance.
We are developing develop video anomaly detection methods suitable for
real-time security applications, within the context of video data
acquired by surveillance cameras in cities like London and Mexico City.
This research involves designing efficient and low complexity visual
data representations, e.g., through feature descriptors, and machine
learning methods suitable for video data.
Person identification through time-invariant face recognition
Temporal-invariant
face recognition allows identifying people using images of faces,
despite the changes due to facial aging. In this project, we are
designing feature descriptors and machine learning approaches that take
into account changes in faces, due to aging, on their associated 3D
shape and texture. We are particularly interested in employing features
learned by Convolutional Neural Networks (CNNs).
Coding of big medical imaging data
Digitization
of whole microscope specimens has recently become possible with the
introduction of high-throughput slide scanners. The digitized versions
of microscope glass slides, which are called virtual slides or
whole-slide images (WSIs), offer several advantages over traditional
glass slides in terms of portability, archival, retrieval, ease of
sharing, and the ability to use computer-aided diagnostic tools.
A key challenge that prevents the potential of WSIs from being fully
exploited is the very large file size, which poses heavy demands on
storage and transmission resources. For example, a typical microscope
specimen of 20 X 30 mm in size usually produces up to 40 GB of uncoded
imaging data using a scanning resolution of 0.2-0.5 micro m. per pixel.
Their very large file size also prevents WSIs from being fully
integrated into Picture Archiving and Communication Systems (PACS) and
the associated DICOM (Digital Imaging and Communications in Medicine)
standard. Therefore, designing efficient and accurate coding methods
capable of facilitating the access, transmission, and visualization of
WSIs remains a challenge.
In this project, we are developing coding methods for access,
transmission, and visualization of WSIs for telepathology applications.
We are particularly interested in facilitating the integration of WSIs
into current PACS while allowing interactive access to the data with
resolution and quality scalability.
Rate-control for High-Dynamic Range (HDR) video coding
Rate
control is an important tool that helps to control the bit rate of the
compressed media. Many current video codecs, such as HEVC
implementations, employ rate control algorithms that are based on
models of the rate-distortion characteristics of the video sequence.
Many of these models, such as the rate-lambda model used in HEVC, do
not consider the wide range of luma values depicted in HDR content.
In this research, we are developing rate control algorithms for HDR
video based on a multi-(rate-lambda) model approach. Our objective is
to accurately attain a target bit rate while improving the
reconstruction quality of HDR content, especially for very bright
regions. Our algorithms are implemented and tested within the HEVC
standard.