840 research outputs found
Map online system using internet-based image catalogue
Digital maps carry along its geodata information such as coordinate that is important in one particular topographic and thematic map. These geodatas are meaningful especially in military field. Since the maps carry along this information, its makes the size of the images is too big. The bigger size, the bigger storage is required to allocate the image file. It also can cause longer loading time. These conditions make it did not suitable to be applied in image catalogue approach via internet environment. With compression techniques, the image size can be reduced and the quality of the image is still guaranteed without much changes. This report is paying attention to one of the image compression technique using wavelet technology. Wavelet technology is much batter than any other image compression technique nowadays. As a result, the compressed images applied to a system called Map Online that used Internet-based Image Catalogue approach. This system allowed user to buy map online. User also can download the maps that had been bought besides using the searching the map. Map searching is based on several meaningful keywords. As a result, this system is expected to be used by Jabatan Ukur dan Pemetaan Malaysia (JUPEM) in order to make the organization vision is implemented
Hierarchical quantization indexing for wavelet and wavelet packet image coding
In this paper, we introduce the quantization index hierarchy, which is used for efficient coding of quantized wavelet and wavelet packet coefficients. A hierarchical classification map is defined in each wavelet subband, which describes the quantized data through a series of index classes. Going from bottom to the top of the tree, neighboring coefficients are combined to form classes that represent some statistics of the quantization indices of these coefficients. Higher levels of the tree are constructed iteratively by repeating this class assignment to partition the coefficients into larger Subsets. The class assignments are optimized using a rate-distortion cost analysis. The optimized tree is coded hierarchically from top to bottom by coding the class membership information at each level of the tree. Context-adaptive arithmetic coding is used to improve coding efficiency. The developed algorithm produces PSNR results that are better than the state-of-art wavelet-based and wavelet packet-based coders in literature.This research was supported by Isik University BAP-05B302 GrantPublisher's Versio
Lossy compression and real-time geovisualization for ultra-low bandwidth telemetry from untethered underwater vehicles
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2008Oceanographic applications of robotics are as varied as the undersea environment itself. As
underwater robotics moves toward the study of dynamic processes with multiple vehicles,
there is an increasing need to distill large volumes of data from underwater vehicles and
deliver it quickly to human operators. While tethered robots are able to communicate data
to surface observers instantly, communicating discoveries is more difficult for untethered
vehicles. The ocean imposes severe limitations on wireless communications; light is quickly
absorbed by seawater, and tradeoffs between frequency, bitrate and environmental effects
result in data rates for acoustic modems that are routinely as low as tens of bits per second.
These data rates usually limit telemetry to state and health information, to the exclusion
of mission-specific science data.
In this thesis, I present a system designed for communicating and presenting science
telemetry from untethered underwater vehicles to surface observers. The system's goals
are threefold: to aid human operators in understanding oceanographic processes, to enable
human operators to play a role in adaptively responding to mission-specific data, and to accelerate mission planning from one vehicle dive to the next. The system uses standard lossy
compression techniques to lower required data rates to those supported by commercially
available acoustic modems (O(10)-O(100) bits per second).
As part of the system, a method for compressing time-series science data based upon
the Discrete Wavelet Transform (DWT) is explained, a number of low-bitrate image compression techniques are compared, and a novel user interface for reviewing transmitted
telemetry is presented. Each component is motivated by science data from a variety of
actual Autonomous Underwater Vehicle (AUV) missions performed in the last year.National Science Foundation Center for Subsurface Sensing and Imaging (CenSSIS ERC
Combined Industry, Space and Earth Science Data Compression Workshop
The sixth annual Space and Earth Science Data Compression Workshop and the third annual Data Compression Industry Workshop were held as a single combined workshop. The workshop was held April 4, 1996 in Snowbird, Utah in conjunction with the 1996 IEEE Data Compression Conference, which was held at the same location March 31 - April 3, 1996. The Space and Earth Science Data Compression sessions seek to explore opportunities for data compression to enhance the collection, analysis, and retrieval of space and earth science data. Of particular interest is data compression research that is integrated into, or has the potential to be integrated into, a particular space or earth science data information system. Preference is given to data compression research that takes into account the scien- tist's data requirements, and the constraints imposed by the data collection, transmission, distribution and archival systems
The JPEG2000 still image compression standard
The development of standards (emerging and established) by the International Organization for Standardization (ISO), the International Telecommunications Union (ITU), and the International Electrotechnical Commission (IEC) for audio, image, and video, for both transmission and storage, has led to worldwide activity in developing hardware and software systems and products applicable to a number of diverse disciplines [7], [22], [23], [55], [56], [73]. Although the standards implicitly address the basic encoding operations, there is freedom and flexibility in the actual design and development of devices. This is because only the syntax and semantics of the bit stream for decoding are specified by standards, their main objective being the compatibility and interoperability among the systems (hardware/software) manufactured by different companies. There is, thus, much room for innovation and ingenuity. Since the mid 1980s, members from both the ITU and the ISO have been working together to establish a joint international standard for the compression of grayscale and color still images. This effort has been known as JPEG, the Join
Progressively communicating rich telemetry from autonomous underwater vehicles via relays
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution June 2012As analysis of imagery and environmental data plays a greater role in mission construction
and execution, there is an increasing need for autonomous marine vehicles
to transmit this data to the surface. Without access to the data acquired by a
vehicle, surface operators cannot fully understand the state of the mission. Communicating
imagery and high-resolution sensor readings to surface observers remains
a significant challenge – as a result, current telemetry from free-roaming
autonomous marine vehicles remains limited to ‘heartbeat’ status messages, with
minimal scientific data available until after recovery. Increasing the challenge, longdistance
communication may require relaying data across multiple acoustic hops
between vehicles, yet fixed infrastructure is not always appropriate or possible.
In this thesis I present an analysis of the unique considerations facing telemetry
systems for free-roaming Autonomous Underwater Vehicles (AUVs) used in exploration.
These considerations include high-cost vehicle nodes with persistent storage
and significant computation capabilities, combined with human surface operators
monitoring each node. I then propose mechanisms for interactive, progressive
communication of data across multiple acoustic hops. These mechanisms include
wavelet-based embedded coding methods, and a novel image compression scheme
based on texture classification and synthesis. The specific characteristics of underwater
communication channels, including high latency, intermittent communication,
the lack of instantaneous end-to-end connectivity, and a broadcast medium,
inform these proposals. Human feedback is incorporated by allowing operators to
identify segments of data thatwarrant higher quality refinement, ensuring efficient
use of limited throughput. I then analyze the performance of these mechanisms
relative to current practices.
Finally, I present CAPTURE, a telemetry architecture that builds on this analysis.
CAPTURE draws on advances in compression and delay tolerant networking to
enable progressive transmission of scientific data, including imagery, across multiple acoustic hops. In concert with a physical layer, CAPTURE provides an endto-
end networking solution for communicating science data from autonomous marine
vehicles. Automatically selected imagery, sonar, and time-series sensor data
are progressively transmitted across multiple hops to surface operators. Human
operators can request arbitrarily high-quality refinement of any resource, up to an
error-free reconstruction. The components of this system are then demonstrated
through three field trials in diverse environments on SeaBED, OceanServer and
Bluefin AUVs, each in different software architectures.Thanks to the National Science Foundation, and the
National Oceanic and Atmospheric Administration for
their funding of my education and this work
Efficient compression of motion compensated residuals
EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Distributed video coding for wireless video sensor networks: a review of the state-of-the-art architectures
Distributed video coding (DVC) is a relatively new video coding architecture originated from two fundamental theorems namely, Slepian–Wolf and Wyner–Ziv. Recent research developments have made DVC attractive for applications in the emerging domain of wireless video sensor networks (WVSNs). This paper reviews the state-of-the-art DVC architectures with a focus on understanding their opportunities and gaps in addressing the operational requirements and application needs of WVSNs
WAVELET BASED DATA HIDING OF DEM IN THE CONTEXT OF REALTIME 3D VISUALIZATION (Visualisation 3D Temps-Réel à Distance de MNT par Insertion de Données Cachées Basée Ondelettes)
The use of aerial photographs, satellite images, scanned maps and digital elevation models necessitates the setting up of strategies for the storage and visualization of these data. In order to obtain a three dimensional visualization it is necessary to drape the images, called textures, onto the terrain geometry, called Digital Elevation Model (DEM). Practically, all these information are stored in three different files: DEM, texture and position/projection of the data in a geo-referential system. In this paper we propose to stock all these information in a single file for the purpose of synchronization. For this we have developed a wavelet-based embedding method for hiding the data in a colored image. The texture images containing hidden DEM data can then be sent from the server to a client in order to effect 3D visualization of terrains. The embedding method is integrable with the JPEG2000 coder to accommodate compression and multi-resolution visualization. Résumé L'utilisation de photographies aériennes, d'images satellites, de cartes scannées et de modèles numériques de terrains amène à mettre en place des stratégies de stockage et de visualisation de ces données. Afin d'obtenir une visualisation en trois dimensions, il est nécessaire de lier ces images appelées textures avec la géométrie du terrain nommée Modèle Numérique de Terrain (MNT). Ces informations sont en pratiques stockées dans trois fichiers différents : MNT, texture, position et projection des données dans un système géo-référencé. Dans cet article, nous proposons de stocker toutes ces informations dans un seul fichier afin de les synchroniser. Nous avons développé pour cela une méthode d'insertion de données cachées basée ondelettes dans une image couleur. Les images de texture contenant les données MNT cachées peuvent ensuite être envoyées du serveur au client afin d'effectuer une visualisation 3D de terrains. Afin de combiner une visualisation en multirésolution et une compression, l'insertion des données cachées est intégrable dans le codeur JPEG 2000
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