5,231 research outputs found
Visualizing and Interacting with Concept Hierarchies
Concept Hierarchies and Formal Concept Analysis are theoretically well
grounded and largely experimented methods. They rely on line diagrams called
Galois lattices for visualizing and analysing object-attribute sets. Galois
lattices are visually seducing and conceptually rich for experts. However they
present important drawbacks due to their concept oriented overall structure:
analysing what they show is difficult for non experts, navigation is
cumbersome, interaction is poor, and scalability is a deep bottleneck for
visual interpretation even for experts. In this paper we introduce semantic
probes as a means to overcome many of these problems and extend usability and
application possibilities of traditional FCA visualization methods. Semantic
probes are visual user centred objects which extract and organize reduced
Galois sub-hierarchies. They are simpler, clearer, and they provide a better
navigation support through a rich set of interaction possibilities. Since probe
driven sub-hierarchies are limited to users focus, scalability is under control
and interpretation is facilitated. After some successful experiments, several
applications are being developed with the remaining problem of finding a
compromise between simplicity and conceptual expressivity
Robot Navigation in Unseen Spaces using an Abstract Map
Human navigation in built environments depends on symbolic spatial
information which has unrealised potential to enhance robot navigation
capabilities. Information sources such as labels, signs, maps, planners, spoken
directions, and navigational gestures communicate a wealth of spatial
information to the navigators of built environments; a wealth of information
that robots typically ignore. We present a robot navigation system that uses
the same symbolic spatial information employed by humans to purposefully
navigate in unseen built environments with a level of performance comparable to
humans. The navigation system uses a novel data structure called the abstract
map to imagine malleable spatial models for unseen spaces from spatial symbols.
Sensorimotor perceptions from a robot are then employed to provide purposeful
navigation to symbolic goal locations in the unseen environment. We show how a
dynamic system can be used to create malleable spatial models for the abstract
map, and provide an open source implementation to encourage future work in the
area of symbolic navigation. Symbolic navigation performance of humans and a
robot is evaluated in a real-world built environment. The paper concludes with
a qualitative analysis of human navigation strategies, providing further
insights into how the symbolic navigation capabilities of robots in unseen
built environments can be improved in the future.Comment: 15 pages, published in IEEE Transactions on Cognitive and
Developmental Systems (http://doi.org/10.1109/TCDS.2020.2993855), see
https://btalb.github.io/abstract_map/ for access to softwar
Video summarisation: A conceptual framework and survey of the state of the art
This is the post-print (final draft post-refereeing) version of the article. Copyright @ 2007 Elsevier Inc.Video summaries provide condensed and succinct representations of the content of a video stream through a combination of still images, video segments, graphical representations and textual descriptors. This paper presents a conceptual framework for video summarisation derived from the research literature and used as a means for surveying the research literature. The framework distinguishes between video summarisation techniques (the methods used to process content from a source video stream to achieve a summarisation of that stream) and video summaries (outputs of video summarisation techniques). Video summarisation techniques are considered within three broad categories: internal (analyse information sourced directly from the video stream), external (analyse information not sourced directly from the video stream) and hybrid (analyse a combination of internal and external information). Video summaries are considered as a function of the type of content they are derived from (object, event, perception or feature based) and the functionality offered to the user for their consumption (interactive or static, personalised or generic). It is argued that video summarisation would benefit from greater incorporation of external information, particularly user based information that is unobtrusively sourced, in order to overcome longstanding challenges such as the semantic gap and providing video summaries that have greater relevance to individual users
User Interfaces for Personal Knowledge Management with Semantic Technologies
This thesis describes iMapping and QuiKey, two novel user interface concepts for dealing with structured information. iMapping is a visual knowledge mapping technique based on zooming, which combines the advantages of several existing approaches and scales up to very large maps. QuiKey is a text-based tool to interact with graph-structured knowledge bases with very high interaction efficiency. Both tools have been implemented and positively evaluated in user studies
Strategies for image visualisation and browsing
PhDThe exploration of large information spaces has remained a challenging task even
though the proliferation of database management systems and the state-of-the art
retrieval algorithms is becoming pervasive. Signi cant research attention in the
multimedia domain is focused on nding automatic algorithms for organising digital
image collections into meaningful structures and providing high-semantic image
indices. On the other hand, utilisation of graphical and interactive methods from
information visualisation domain, provide promising direction for creating e cient
user-oriented systems for image management. Methods such as exploratory browsing
and query, as well as intuitive visual overviews of image collection, can assist
the users in nding patterns and developing the understanding of structures and
content in complex image data-sets.
The focus of the thesis is combining the features of automatic data processing
algorithms with information visualisation. The rst part of this thesis focuses on
the layout method for displaying the collection of images indexed by low-level visual
descriptors. The proposed solution generates graphical overview of the data-set as
a combination of similarity based visualisation and random layout approach.
Second part of the thesis deals with problem of visualisation and exploration for
hierarchical organisation of images. Due to the absence of the semantic information,
images are considered the only source of high-level information. The content preview
and display of hierarchical structure are combined in order to support image
retrieval. In addition to this, novel exploration and navigation methods are proposed
to enable the user to nd the way through database structure and retrieve
the content.
On the other hand, semantic information is available in cases where automatic
or semi-automatic image classi ers are employed. The automatic annotation of
image items provides what is referred to as higher-level information. This type
of information is a cornerstone of multi-concept visualisation framework which is
developed as a third part of this thesis. This solution enables dynamic generation
of user-queries by combining semantic concepts, supported by content overview and
information ltering.
Comparative analysis and user tests, performed for the evaluation of the proposed
solutions, focus on the ways information visualisation a ects the image content
exploration and retrieval; how e cient and comfortable are the users when
using di erent interaction methods and the ways users seek for information through
di erent types of database organisation
Relational navigation and archiving of multimedia information for contemporary dance
Dissertação para obtenção do Grau de Mestre em
Engenharia InformáticaTechnology continues to evolve at an incredible rate and with it, the number of people adhering to new digital trends. As the production of multimedia content such as photographs and videos becomes accessible to more people every year, so does the amount
of digital content increase exponentially. Consequently, it becomes a hard task to create systems in order to provide efficient storing and browsing of multimedia content.
Multimedia Web archives are one of the most popular solutions found for these issues.
By providing organized and connected information storage with efficient browsing and social networking features, these systems become the main platforms used to store and share photographs and videos in the internet.
This work is done in the scope of the TKB project: Transmedia Knowledge Base for Contemporary Dance and the goal of this thesis is to develop a system for multimedia information storage and relational content navigation. The analysis of multimedia archiving systems done throughout this thesis extends to those specific for Contemporary dance as it is one of the main focus of the work. The contents which will be integrated in the archive include typical multimedia information such as images and videos, as well as annotated videos exported from specific platforms. Connecting all the information within the archive through taxonomy and content hierarchy allows the definition of the intended relational approach. Setting connections between content and users allow the creation of graphs, which will serve as a basis for all the browsing, navigation and searching done throughout the system.TKB project- A Transmedia Knowledge Base for contemporary dance(PTDC/EAT-AVP/098220/2008
CHORUS Deliverable 2.1: State of the Art on Multimedia Search Engines
Based on the information provided by European projects and national initiatives related to multimedia search as well as domains experts that participated in the CHORUS Think-thanks and workshops, this document reports on the state of the art related to multimedia content search from, a technical, and socio-economic perspective.
The technical perspective includes an up to date view on content based indexing and retrieval technologies, multimedia search in the context of mobile devices and peer-to-peer networks, and an overview of current evaluation and benchmark inititiatives to measure the performance of multimedia search engines.
From a socio-economic perspective we inventorize the impact and legal consequences of these technical advances and point out future directions of research
Scalable Exploration of Complex Objects and Environments Beyond Plain Visual Replication
Digital multimedia content and presentation means are rapidly increasing their sophistication and are now capable of describing detailed representations of the physical world. 3D exploration experiences allow people to appreciate, understand and interact with intrinsically virtual objects.
Communicating information on objects requires the ability to explore them under different angles, as well as to mix highly photorealistic or illustrative presentations of the object themselves with additional data that provides additional insights on these objects, typically represented in the form of annotations. Effectively providing these capabilities requires the solution of important problems in visualization and user interaction.
In this thesis, I studied these problems in the cultural heritage-computing-domain, focusing on the very common and important special case of mostly planar, but visually, geometrically, and semantically rich objects. These could be generally roughly flat objects with a standard frontal viewing direction (e.g., paintings, inscriptions, bas-reliefs), as well as visualizations of fully 3D objects from a particular point of views (e.g., canonical views of buildings or statues). Selecting a precise application domain and a specific presentation mode allowed me to concentrate on the well defined use-case of the exploration of annotated relightable stratigraphic models (in particular, for local and remote museum presentation).
My main results and contributions to the state of the art have been a novel technique for interactively controlling visualization lenses while automatically maintaining good focus-and-context parameters, a novel approach for avoiding clutter in an annotated model and for guiding users towards interesting areas, and a method for structuring audio-visual object annotations into a graph and for using that graph to improve guidance and support storytelling and automated tours.
We demonstrated the effectiveness and potential of our techniques by performing interactive exploration sessions on various screen sizes and types ranging from desktop devices to large-screen displays for a walk-up-and-use museum installation.
KEYWORDS - Computer Graphics, Human-Computer Interaction, Interactive Lenses, Focus-and-Context, Annotated Models, Cultural Heritage Computing
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