To Draw or Not to Draw: Recognizing Stroke-Hover Intent in Gesture-Free Bare-Hand Mid-Air Drawing Tasks

Over the past several decades, technological advancements have introduced new modes of communication with the computers, introducing a shift from traditional mouse and keyboard interfaces. While touch based interactions are abundantly being used today, latest developments in computer vision, body tracking stereo cameras, and augmented and virtual reality have now enabled communicating with the computers using spatial input in the physical 3D space. These techniques are now being integrated into several design critical tasks like sketching, modeling, etc. through sophisticated methodologies and use of specialized instrumented devices. One of the prime challenges in design research is to make this spatial interaction with the computer as intuitive as possible for the users. Drawing curves in mid-air with fingers, is a fundamental task with applications to 3D sketching, geometric modeling, handwriting recognition, and authentication. Sketching in general, is a crucial mode for effective idea communication between designers. Mid-air curve input is typically accomplished through instrumented controllers, specific hand postures, or pre-defined hand gestures, in presence of depth and motion sensing cameras. The user may use any of these modalities to express the intention to start or stop sketching. However, apart from suffering with issues like lack of robustness, the use of such gestures, specific postures, or the necessity of instrumented controllers for design specific tasks further result in an additional cognitive load on the user. To address the problems associated with different mid-air curve input modalities, the presented research discusses the design, development, and evaluation of data driven models for intent recognition in non-instrumented, gesture-free, bare-hand mid-air drawing tasks. The research is motivated by a behavioral study that demonstrates the need for such an approach due to the lack of robustness and intuitiveness while using hand postures and instrumented devices. The main objective is to study how users move during mid-air sketching, develop qualitative insights regarding such movements, and consequently implement a computational approach to determine when the user intends to draw in mid-air without the use of an explicit mechanism (such as an instrumented controller or a specified hand-posture). By recording the user’s hand trajectory, the idea is to simply classify this point as either hover or stroke. The resulting model allows for the classification of points on the user’s spatial trajectory. Drawing inspiration from the way users sketch in mid-air, this research first specifies the necessity for an alternate approach for processing bare hand mid-air curves in a continuous fashion. Further, this research presents a novel drawing intent recognition work flow for every recorded drawing point, using three different approaches. We begin with recording mid-air drawing data and developing a classification model based on the extracted geometric properties of the recorded data. The main goal behind developing this model is to identify drawing intent from critical geometric and temporal features. In the second approach, we explore the variations in prediction quality of the model by improving the dimensionality of data used as mid-air curve input. Finally, in the third approach, we seek to understand the drawing intention from mid-air curves using sophisticated dimensionality reduction neural networks such as autoencoders. Finally, the broad level implications of this research are discussed, with potential development areas in the design and research of mid-air interactions

Dynamic motion coupling of body movement for input control

Touchless gestures are used for input when touch is unsuitable or unavailable, such as when interacting with displays that are remote, large, public, or when touch is prohibited for hygienic reasons. Traditionally user input is spatially or semantically mapped to system output, however, in the context of touchless gestures these interaction principles suffer from several disadvantages including memorability, fatigue, and ill-defined mappings. This thesis investigates motion correlation as the third interaction principle for touchless gestures, which maps user input to system output based on spatiotemporal matching of reproducible motion. We demonstrate the versatility of motion correlation by using movement as the primary sensing principle, relaxing the restrictions on how a user provides input. Using TraceMatch, a novel computer vision-based system, we show how users can provide effective input through investigation of input performance with different parts of the body, and how users can switch modes of input spontaneously in realistic application scenarios. Secondly, spontaneous spatial coupling shows how motion correlation can bootstrap spatial input, allowing any body movement, or movement of tangible objects, to be appropriated for ad hoc touchless pointing on a per interaction basis. We operationalise the concept in MatchPoint, and demonstrate the unique capabilities through an exploration of the design space with application examples. Finally, we explore how users synchronise with moving targets in the context of motion correlation, revealing how simple harmonic motion leads to better synchronisation. Using the insights gained we explore the robustness of algorithms used for motion correlation, showing how it is possible to successfully detect a user's intent to interact whilst suppressing accidental activations from common spatial and semantic gestures. Finally, we look across our work to distil guidelines for interface design, and further considerations of how motion correlation can be used, both in general and for touchless gestures

Automotive gestures recognition based on capacitive sensing

Dissertação de mestrado integrado em Engenharia Eletrónica Industrial e ComputadoresDriven by technological advancements, vehicles have steadily increased in sophistication, specially in the way drivers and passengers interact with their vehicles. For example, the BMW 7 series driver-controlled systems, contains over 700 functions. Whereas, it makes easier to navigate streets, talk on phone and more, this may lead to visual distraction, since when paying attention to a task not driving related, the brain focus on that activity. That distraction is, according to studies, the third cause of accidents, only surpassed by speeding and drunk driving. Driver distraction is stressed as the main concern by regulators, in particular, National Highway Transportation Safety Agency (NHTSA), which is developing recommended limits for the amount of time a driver needs to spend glancing away from the road to operate in-car features. Diverting attention from driving can be fatal; therefore, automakers have been challenged to design safer and comfortable human-machine interfaces (HMIs) without missing the latest technological achievements. This dissertation aims to mitigate driver distraction by developing a gestural recognition system that allows the user a more comfortable and intuitive experience while driving. The developed system outlines the algorithms to recognize gestures using the capacitive technology.Impulsionados pelos avanços tecnológicos, os automóveis tem de forma continua aumentado em complexidade, sobretudo na forma como os conductores e passageiros interagem com os seus veículos. Por exemplo, os sistemas controlados pelo condutor do BMW série 7 continham mais de 700 funções. Embora, isto facilite a navegação entre locais, falar ao telemóvel entre outros, isso pode levar a uma distração visual, já que ao prestar atenção a uma tarefa não relacionados com a condução, o cérebro se concentra nessa atividade. Essa distração é, de acordo com os estudos, a terceira causa de acidentes, apenas ultrapassada pelo excesso de velocidade e condução embriagada. A distração do condutor é realçada como a principal preocupação dos reguladores, em particular, a National Highway Transportation Safety Agency (NHTSA), que está desenvolvendo os limites recomendados para a quantidade de tempo que um condutor precisa de desviar o olhar da estrada para controlar os sistemas do carro. Desviar a atenção da conducção, pode ser fatal; portanto, os fabricante de automóveis têm sido desafiados a projetar interfaces homemmáquina (HMIs) mais seguras e confortáveis, sem perder as últimas conquistas tecnológicas. Esta dissertação tem como objetivo minimizar a distração do condutor, desenvolvendo um sistema de reconhecimento gestual que permite ao utilizador uma experiência mais confortável e intuitiva ao conduzir. O sistema desenvolvido descreve os algoritmos de reconhecimento de gestos usando a tecnologia capacitiva.It is worth noting that this work has been financially supported by the Portugal Incentive System for Research and Technological Development in scope of the projects in co-promotion number 036265/2013 (HMIExcel 2013-2015), number 002814/2015 (iFACTORY 2015-2018) and number 002797/2015 (INNOVCAR 2015-2018)

Effective Identity Management on Mobile Devices Using Multi-Sensor Measurements

Due to the dramatic increase in popularity of mobile devices in the past decade, sensitive user information is stored and accessed on these devices every day. Securing sensitive data stored and accessed from mobile devices, makes user-identity management a problem of paramount importance. The tension between security and usability renders the task of user-identity verification on mobile devices challenging. Meanwhile, an appropriate identity management approach is missing since most existing technologies for user-identity verification are either one-shot user verification or only work in restricted controlled environments. To solve the aforementioned problems, we investigated and sought approaches from the sensor data generated by human-mobile interactions. The data are collected from the on-board sensors, including voice data from microphone, acceleration data from accelerometer, angular acceleration data from gyroscope, magnetic force data from magnetometer, and multi-touch gesture input data from touchscreen. We studied the feasibility of extracting biometric and behaviour features from the on-board sensor data and how to efficiently employ the features extracted to perform user-identity verification on the smartphone device. Based on the experimental results of the single-sensor modalities, we further investigated how to integrate them with hardware such as fingerprint and Trust Zone to practically fulfill a usable identity management system for both local application and remote services control. User studies and on-device testing sessions were held for privacy and usability evaluation.Computer Science, Department o

Teaching Introductory Programming Concepts through a Gesture-Based Interface

Computer programming is an integral part of a technology driven society, so there is a tremendous need to teach programming to a wider audience. One of the challenges in meeting this demand for programmers is that most traditional computer programming classes are targeted to university/college students with strong math backgrounds. To expand the computer programming workforce, we need to encourage a wider range of students to learn about programming. The goal of this research is to design and implement a gesture-driven interface to teach computer programming to young and non-traditional students. We designed our user interface based on the feedback from students attending the College of Engineering summer camps at the University of Arkansas. Our system uses the Microsoft Xbox Kinect to capture the movements of new programmers as they use our system. Our software then tracks and interprets student hand movements in order to recognize specific gestures which correspond to different programming constructs, and uses this information to create and execute programs using the Google Blockly visual programming framework. We focus on various gesture recognition algorithms to interpret user data as specific gestures, including template matching, sector quantization, and supervised machine learning clustering algorithms

Sign Language Tutoring Tool

In this project, we have developed a sign language tutor that lets users learn isolated signs by watching recorded videos and by trying the same signs. The system records the user's video and analyses it. If the sign is recognized, both verbal and animated feedback is given to the user. The system is able to recognize complex signs that involve both hand gestures and head movements and expressions. Our performance tests yield a 99% recognition rate on signs involving only manual gestures and 85% recognition rate on signs that involve both manual and non manual components, such as head movement and facial expressions.Comment: eNTERFACE'06. Summer Workshop. on Multimodal Interfaces, Dubrovnik : Croatie (2007