113 research outputs found
deForm: An interactive malleable surface for capturing 2.5D arbitrary objects, tools and touch
We introduce a novel input device, deForm, that supports 2.5D touch gestures, tangible tools, and arbitrary objects through real-time structured light scanning of a malleable surface of interaction. DeForm captures high-resolution surface deformations and 2D grey-scale textures of a gel surface through a three-phase structured light 3D scanner. This technique can be combined with IR projection to allow for invisible capture, providing the opportunity for co-located visual feedback on the deformable surface. We describe methods for tracking fingers, whole hand gestures, and arbitrary tangible tools. We outline a method for physically encoding fiducial marker information in the height map of tangible tools. In addition, we describe a novel method for distinguishing between human touch and tangible tools, through capacitive sensing on top of the input surface. Finally we motivate our device through a number of sample applications
Object representation and recognition
One of the primary functions of the human visual system is object recognition, an ability that allows us to relate the visual stimuli falling on our retinas to our knowledge of the world. For example, object recognition allows you to use knowledge of what an apple looks like to find it in the supermarket, to use knowledge of what a shark looks like to swim in th
Symmetry in 3D shapes - analysis and applications to model synthesis
Symmetry is an essential property of a shapes\u27 appearance and presents a source of information for structure-aware deformation and model synthesis. This thesis proposes feature-based methods to detect symmetry and regularity in 3D shapes and demonstrates the utilization of symmetry information for content generation. First, we will introduce two novel feature detection techniques that extract salient keypoints and feature lines for a 3D shape respectively. Further, we will propose a randomized, feature-based approach to detect symmetries and decompose the shape into recurring building blocks. Then, we will present the concept of docking sites that allows us to derive a set of shape operations from an exemplar and will produce similar shapes. This is a key insight of this thesis and opens up a new perspective on inverse procedural modeling. Finally, we will present an interactive, structure-aware deformation technique based entirely on regular patterns.Symmetrie ist eine essentielle Eigenschaft fĂŒr das Aussehen eines Objekts und bietet eine Informationsquelle fĂŒr strukturerhaltende Deformation und Modellsynthese. Diese Arbeit beschĂ€ftigt sich mit merkmalsbasierter Symmetrieerkennung in 3D-Objekten und der Synthese von 3D-Modellen mittels Symmetrieinformationen. ZunĂ€chst stellen wir zwei neue Verfahren zur Merkmalserkennung vor, die hervorstechende Punkte bzw. Linien in 3D-Objekten erkennen. Darauf aufbauend beschreiben wir einen randomisierten, merkmalsbasierten Ansatz zur Symmetrieerkennung, der ein Objekt in sich wiederholende Bausteine zerlegt. Des Weiteren fĂŒhren wir ein Konzept zur Modifikation von Objekten ein, welches Andockstellen in Geometrie berechnet und zur Generierung von Ă€hnlichen Objekten eingesetzt werden kann. Dieses Konzept eröffnet völlig neue Möglichkeiten fĂŒr die Ermittlung von prozeduralen Regeln aus Beispielen. Zum Schluss prĂ€sentieren wir eine interaktive Technik zur strukturerhaltenden Deformation, welche komplett auf regulĂ€ren Strukturen basiert
Remixing physical objects through tangible tools
Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2011.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student submitted PDF version of thesis.Includes bibliographical references (p. 147-164).In this document we present new tools for remixing physical objects. These tools allow users to copy, edit and manipulate the properties of one or more objects to create a new physical object. We already have these capabilities using digital media: we can easily mash up videos, music and text. However, it remains difficult to remix physical objects and we cannot access the advantages of digital media, which are nondestructive, scalable and scriptable. We can bridge this gap by both integrating 2D and 3D scanning technology into design tools and employing aordable rapid prototyping technology to materialize these remixed objects. In so doing, we hope to promote copying as a tool for creation. This document presents two tools, CopyCAD and KidCAD, the first designed for makers and crafters, the second for children. CopyCAD is an augmented Computer Numerically Controlled (CNC) milling machine which allows users to copy arbitrary real world object geometry into 2D CAD designs at scale through the use of a camera-projector system. CopyCAD gathers properties from physical objects, sketches and touch interactions directly on a milling machine, allowing novice users to copy parts of real world objects, modify them and create a new physical part. KidCAD is a sculpting interface built on top of a gel-based realtime 2.5D scanner. It allows children to stamp objects into the block of gel, which are scanned in realtime, as if they were stamped into clay. Children can use everyday objects, their hands and tangible tools to design new toys or objects that will be 3D printed. This work enables novice users to easily approach designing physical objects by copying from other objects and sketching new designs. With increased access to such tools we hope that a wide range of people will be empowered to create their own objects, toys, tools and parts.by Sean Follmer.S.M
Rapid Prototyping Using Three-Dimensional Computer Vision
A method for building model data for CAD and CAM purposes from physical instances using three-dimensional sensor data is presented. These techniques are suitable for Reverse Engineering of industrial parts, and can be used as a design aid as well. The nature of the reverse engineering task is quantitative, and the emphasis is on accurate recovery of the geometry of the part, whereas the object recognition task is qualitative, and aims to recognize similar shapes. The proposed method employs multiple representation to build a CAD model for the part, and to produce useful information for part analysis and process planning. The model building strategy is selected based on the obtained surface and volumetric data descriptions and their quality. A novel, robust non-linear filtering method is presented to attenuate noise from sensor data. Volumetric description is obtained by recovering a superquadric model for the whole data set. A surface characterization process is used to determine the complexity of the underlying surface. A substantial data compression can be obtained by approximating huge amount sensor data by B-spline surfaces. As a result a Boundary Representation model for Alpha-1 solid modeling system is constructed. The model data is represented both in Alpha-1 modeling language and IGES product data exchange format. Experimental results for standard geometric shapes and for sculptured free-form surfaces are presented using both real and synthetic range data
Embodied Interactions for Spatial Design Ideation: Symbolic, Geometric, and Tangible Approaches
Computer interfaces are evolving from mere aids for number crunching into active partners in creative processes such as art and design. This is, to a great extent, the result of mass availability of new interaction technology such as depth sensing, sensor integration in mobile devices, and increasing computational power. We are now witnessing the emergence of maker culture that can elevate art and design beyond the purview of enterprises and professionals such as trained engineers and artists. Materializing this transformation is not trivial; everyone has ideas but only a select few can bring them to reality. The challenge is the recognition and the subsequent interpretation of human actions into design intent
TAP-Vid: A Benchmark for Tracking Any Point in a Video
Generic motion understanding from video involves not only tracking objects,
but also perceiving how their surfaces deform and move. This information is
useful to make inferences about 3D shape, physical properties and object
interactions. While the problem of tracking arbitrary physical points on
surfaces over longer video clips has received some attention, no dataset or
benchmark for evaluation existed, until now. In this paper, we first formalize
the problem, naming it tracking any point (TAP). We introduce a companion
benchmark, TAP-Vid, which is composed of both real-world videos with accurate
human annotations of point tracks, and synthetic videos with perfect
ground-truth point tracks. Central to the construction of our benchmark is a
novel semi-automatic crowdsourced pipeline which uses optical flow estimates to
compensate for easier, short-term motion like camera shake, allowing annotators
to focus on harder sections of video. We validate our pipeline on synthetic
data and propose a simple end-to-end point tracking model TAP-Net, showing that
it outperforms all prior methods on our benchmark when trained on synthetic
data.Comment: Published in NeurIPS Datasets and Benchmarks track, 202
Grasp-sensitive surfaces
Grasping objects with our hands allows us to skillfully move and manipulate them.
Hand-held tools further extend our capabilities by adapting precision, power, and shape of our hands to the task at hand.
Some of these tools, such as mobile phones or computer mice, already incorporate information processing capabilities.
Many other tools may be augmented with small, energy-efficient digital sensors and processors.
This allows for graspable objects to learn about the user grasping them - and supporting the user's goals.
For example, the way we grasp a mobile phone might indicate whether we want to take a photo or call a friend with it - and thus serve as a shortcut to that action.
A power drill might sense whether the user is grasping it firmly enough and refuse to turn on if this is not the case.
And a computer mouse could distinguish between intentional and unintentional movement and ignore the latter.
This dissertation gives an overview of grasp sensing for human-computer interaction, focusing on technologies for building grasp-sensitive surfaces and challenges in designing grasp-sensitive user interfaces.
It comprises three major contributions: a comprehensive review of existing research on human grasping and grasp sensing, a detailed description of three novel prototyping tools for grasp-sensitive surfaces, and a framework for analyzing and designing grasp interaction:
For nearly a century, scientists have analyzed human grasping.
My literature review gives an overview of definitions, classifications, and models of human grasping.
A small number of studies have investigated grasping in everyday situations.
They found a much greater diversity of grasps than described by existing taxonomies.
This diversity makes it difficult to directly associate certain grasps with users' goals.
In order to structure related work and own research, I formalize a generic workflow for grasp sensing.
It comprises *capturing* of sensor values, *identifying* the associated grasp, and *interpreting* the meaning of the grasp.
A comprehensive overview of related work shows that implementation of grasp-sensitive surfaces is still hard, researchers often are not aware of related work from other disciplines, and intuitive grasp interaction has not yet received much attention.
In order to address the first issue, I developed three novel sensor technologies designed for grasp-sensitive surfaces. These mitigate one or more limitations of traditional sensing techniques:
**HandSense** uses four strategically positioned capacitive sensors for detecting and classifying grasp patterns on mobile phones. The use of custom-built high-resolution sensors allows detecting proximity and avoids the need to cover the whole device surface with sensors. User tests showed a recognition rate of 81%, comparable to that of a system with 72 binary sensors.
**FlyEye** uses optical fiber bundles connected to a camera for detecting touch and proximity on arbitrarily shaped surfaces. It allows rapid prototyping of touch- and grasp-sensitive objects and requires only very limited electronics knowledge. For FlyEye I developed a *relative calibration* algorithm that allows determining the locations of groups of sensors whose arrangement is not known.
**TDRtouch** extends Time Domain Reflectometry (TDR), a technique traditionally used for inspecting cable faults, for touch and grasp sensing. TDRtouch is able to locate touches along a wire, allowing designers to rapidly prototype and implement modular, extremely thin, and flexible grasp-sensitive surfaces.
I summarize how these technologies cater to different requirements and significantly expand the design space for grasp-sensitive objects.
Furthermore, I discuss challenges for making sense of raw grasp information and categorize interactions. Traditional application scenarios for grasp sensing use only the grasp sensor's data, and only for mode-switching. I argue that data from grasp sensors is part of the general usage context and should be only used in combination with other context information.
For analyzing and discussing the possible meanings of grasp types, I created the GRASP model. It describes five categories of influencing factors that determine how we grasp an object:
*Goal* -- what we want to do with the object,
*Relationship* -- what we know and feel about the object we want to grasp,
*Anatomy* -- hand shape and learned movement patterns,
*Setting* -- surrounding and environmental conditions, and
*Properties* -- texture, shape, weight, and other intrinsics of the object
I conclude the dissertation with a discussion of upcoming challenges in grasp sensing and grasp interaction, and provide suggestions for implementing robust and usable grasp interaction.Die FÀhigkeit, GegenstÀnde mit unseren HÀnden zu greifen, erlaubt uns, diese vielfÀltig zu manipulieren.
Werkzeuge erweitern unsere FĂ€higkeiten noch, indem sie Genauigkeit, Kraft und Form unserer HĂ€nde an die Aufgabe anpassen.
Digitale Werkzeuge, beispielsweise Mobiltelefone oder ComputermÀuse, erlauben uns auch, die FÀhigkeiten unseres Gehirns und unserer Sinnesorgane zu erweitern.
Diese GerĂ€te verfĂŒgen bereits ĂŒber Sensoren und Recheneinheiten.
Aber auch viele andere Werkzeuge und Objekte lassen sich mit winzigen, effizienten Sensoren und Recheneinheiten erweitern.
Dies erlaubt greifbaren Objekten, mehr ĂŒber den Benutzer zu erfahren, der sie greift - und ermöglicht es, ihn bei der Erreichung seines Ziels zu unterstĂŒtzen.
Zum Beispiel könnte die Art und Weise, in der wir ein Mobiltelefon halten, verraten, ob wir ein Foto aufnehmen oder einen Freund anrufen wollen - und damit als Shortcut fĂŒr diese Aktionen dienen.
Eine Bohrmaschine könnte erkennen, ob der Benutzer sie auch wirklich sicher hÀlt und den Dienst verweigern, falls dem nicht so ist.
Und eine Computermaus könnte zwischen absichtlichen und unabsichtlichen Mausbewegungen unterscheiden und letztere ignorieren.
Diese Dissertation gibt einen Ăberblick ĂŒber Grifferkennung (*grasp sensing*) fĂŒr die Mensch-Maschine-Interaktion, mit einem Fokus auf Technologien zur Implementierung griffempfindlicher OberflĂ€chen und auf Herausforderungen beim Design griffempfindlicher Benutzerschnittstellen.
Sie umfasst drei primÀre BeitrÀge zum wissenschaftlichen Forschungsstand:
einen umfassenden Ăberblick ĂŒber die bisherige Forschung zu menschlichem Greifen und Grifferkennung,
eine detaillierte Beschreibung dreier neuer Prototyping-Werkzeuge fĂŒr griffempfindliche OberflĂ€chen
und ein Framework fĂŒr Analyse und Design von griff-basierter Interaktion (*grasp interaction*).
Seit nahezu einem Jahrhundert erforschen Wissenschaftler menschliches Greifen.
Mein Ăberblick ĂŒber den Forschungsstand beschreibt Definitionen, Klassifikationen und Modelle menschlichen Greifens.
In einigen wenigen Studien wurde bisher Greifen in alltÀglichen Situationen untersucht.
Diese fanden eine deutlich gröĂere DiversitĂ€t in den Griffmuster als in existierenden Taxonomien beschreibbar.
Diese DiversitÀt erschwert es, bestimmten Griffmustern eine Absicht des Benutzers zuzuordnen.
Um verwandte Arbeiten und eigene Forschungsergebnisse zu strukturieren, formalisiere ich einen allgemeinen Ablauf der Grifferkennung.
Dieser besteht aus dem *Erfassen* von Sensorwerten, der *Identifizierung* der damit verknĂŒpften Griffe und der *Interpretation* der Bedeutung des Griffes.
In einem umfassenden Ăberblick ĂŒber verwandte Arbeiten zeige ich, dass die Implementierung von griffempfindlichen OberflĂ€chen immer noch ein herausforderndes Problem ist, dass Forscher regelmĂ€Ăig keine Ahnung von verwandten Arbeiten in benachbarten Forschungsfeldern haben, und dass intuitive Griffinteraktion bislang wenig Aufmerksamkeit erhalten hat.
Um das erstgenannte Problem zu lösen, habe ich drei neuartige Sensortechniken fĂŒr griffempfindliche OberflĂ€chen entwickelt.
Diese mindern jeweils eine oder mehrere SchwÀchen traditioneller Sensortechniken:
**HandSense** verwendet vier strategisch positionierte kapazitive Sensoren um Griffmuster zu erkennen.
Durch die Verwendung von selbst entwickelten, hochauflösenden Sensoren ist es möglich, schon die AnnÀherung an das Objekt zu erkennen.
AuĂerdem muss nicht die komplette OberflĂ€che des Objekts mit Sensoren bedeckt werden.
Benutzertests ergaben eine Erkennungsrate, die vergleichbar mit einem System mit 72 binÀren Sensoren ist.
**FlyEye** verwendet LichtwellenleiterbĂŒndel, die an eine Kamera angeschlossen werden, um AnnĂ€herung und BerĂŒhrung auf beliebig geformten OberflĂ€chen zu erkennen.
Es ermöglicht auch Designern mit begrenzter Elektronikerfahrung das Rapid Prototyping von berĂŒhrungs- und griffempfindlichen Objekten.
FĂŒr FlyEye entwickelte ich einen *relative-calibration*-Algorithmus, der verwendet werden kann um Gruppen von Sensoren, deren Anordnung unbekannt ist, semi-automatisch anzuordnen.
**TDRtouch** erweitert Time Domain Reflectometry (TDR), eine Technik die ĂŒblicherweise zur Analyse von KabelbeschĂ€digungen eingesetzt wird.
TDRtouch erlaubt es, BerĂŒhrungen entlang eines Drahtes zu lokalisieren.
Dies ermöglicht es, schnell modulare, extrem dĂŒnne und flexible griffempfindliche OberflĂ€chen zu entwickeln.
Ich beschreibe, wie diese Techniken verschiedene Anforderungen erfĂŒllen und den *design space* fĂŒr griffempfindliche Objekte deutlich erweitern.
Desweiteren bespreche ich die Herausforderungen beim Verstehen von Griffinformationen und
stelle eine Einteilung von Interaktionsmöglichkeiten vor.
Bisherige Anwendungsbeispiele fĂŒr die Grifferkennung nutzen nur Daten der Griffsensoren und beschrĂ€nken sich auf Moduswechsel.
Ich argumentiere, dass diese Sensordaten Teil des allgemeinen Benutzungskontexts sind und nur in Kombination mit anderer Kontextinformation verwendet werden sollten.
Um die möglichen Bedeutungen von Griffarten analysieren und diskutieren zu können, entwickelte ich das GRASP-Modell.
Dieses beschreibt fĂŒnf Kategorien von Einflussfaktoren, die bestimmen wie wir ein Objekt greifen:
*Goal* -- das Ziel, das wir mit dem Griff erreichen wollen,
*Relationship* -- das VerhÀltnis zum Objekt,
*Anatomy* -- Handform und Bewegungsmuster,
*Setting* -- Umgebungsfaktoren und
*Properties* -- Eigenschaften des Objekts, wie OberflÀchenbeschaffenheit, Form oder Gewicht.
Ich schlieĂe mit einer Besprechung neuer Herausforderungen bei der Grifferkennung und Griffinteraktion und mache VorschlĂ€ge zur Entwicklung von zuverlĂ€ssiger und benutzbarer Griffinteraktion
Retinal vessel segmentation using textons
Segmenting vessels from retinal images, like segmentation in many other medical image domains, is a challenging task, as there is no unified way that can be adopted to extract the vessels accurately. However, it is the most critical stage in automatic assessment of various forms of diseases (e.g. Glaucoma, Age-related macular degeneration, diabetic retinopathy and cardiovascular diseases etc.). Our research aims to investigate retinal image segmentation approaches based on textons as they provide a compact description of texture that can be learnt from a training set. This thesis presents a brief review of those diseases and also includes their current situations, future trends and techniques used for their automatic diagnosis in routine clinical applications. The importance of retinal vessel segmentation is
particularly emphasized in such applications. An extensive review of previous work on retinal vessel segmentation and salient texture analysis methods is presented. Five automatic retinal vessel segmentation methods are proposed in this thesis. The first method focuses on addressing the problem of removing pathological anomalies (Drusen, exudates) for retinal vessel segmentation, which have been identified by other researchers as a problem and a common source of error. The results show that the modified method shows some
improvement compared to a previously published method. The second novel supervised segmentation method employs textons. We propose a new filter bank (MR11) that includes bar detectors for vascular feature extraction and other kernels to detect edges and photometric variations in the image. The k-means clustering algorithm is adopted for texton generation based on the vessel and non-vessel elements which are identified by ground truth. The third improved supervised method is developed based on the second one, in which textons are generated by k-means clustering and texton maps representing vessels are derived by back projecting pixel clusters onto hand labelled ground truth. A further step is implemented to ensure that the best combinations of textons are represented in the map and subsequently used to identify vessels in the test set. The experimental results on two benchmark datasets show that our proposed method performs well compared to other published work and the results of human experts. A further test of our system on an independent set of optical fundus images verified its consistent performance. The statistical analysis on experimental results also reveals that it is possible to train unified textons for retinal vessel segmentation. In the fourth method a novel scheme using Gabor filter bank for vessel feature extraction is proposed. The ii method is inspired by the human visual system. Machine learning is used to optimize the
Gabor filter parameters. The experimental results demonstrate that our method significantly enhances the true positive rate while maintaining a level of specificity that is comparable with other approaches. Finally, we proposed a new unsupervised texton based retinal vessel
segmentation method using derivative of SIFT and multi-scale Gabor filers. The lack of sufficient quantities of hand labelled ground truth and the high level of variability in ground truth labels amongst experts provides the motivation for this approach. The evaluation results
reveal that our unsupervised segmentation method is comparable with the best other supervised methods and other best state of the art methods
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