Pen-based interfaces utilize sketch recognition so users can create and interact with complex, graphical systems via drawn input. In order for people to freely draw within these systems, users' drawing styles should not be constrained. The low-level techniques involved with sketch recognition must then be perfected, because poor low-level accuracy can impair a user's interaction experience. Corner finding, also known as stroke segmentation, is one of the first steps to free-form sketch recognition. Corner finding breaks a drawn stroke into a set of primitive symbols such as lines, arcs, and circles, so that the original stoke data can be transformed into a more machine-friendly format. By working with sketched primitives, drawn objects can then be described in a visual language, noting what primitive shapes have been drawn and the shapes? geometric relationships to each other. We present three new corner finding techniques that improve segmentation accuracy. Our first technique, MergeCF, is a multi-primitive segmenter that splits drawn strokes into primitive lines and arcs. MergeCF eliminates extraneous primitives by merging them with their neighboring segments. Our second technique, ShortStraw, works with polyline-only data. Polyline segments are important since many domains use simple polyline symbols formed with squares, triangles, and arrows. Our ShortStraw algorithm is simple to implement, yet more powerful than previous polyline work in the corner finding literature. Lastly, we demonstrate how a combination technique can be used to pull the best corner finding results from multiple segmentation algorithms. This combination segmenter utilizes the best corners found from other segmentation techniques, eliminating many false negatives (missed primitive segmentations) from the final, low-level results. We will present the implementation and results from our new segmentation techniques, showing how they perform better than related work in the corner finding field. We will also discuss limitations of each technique, how we have sought to overcome those limitations, and where we believe the sketch recognition subfield of corner finding is headed.

Sketch recognition allows computers to understand and model hand drawn sketches and diagrams. Traditionally sketch recognition systems required a pen based PC interface, but powerful mobile devices such as tablets and smartphones can provide a new platform for sketch recognition systems. We describe a new sketch recognition library, Strontium (SrL) that combines several existing sketch recognition libraries modified to run on both personal computers and on the Android platform. We analyzed the recognition speed and accuracy implications of performing low-level shape recognition on smartphones with touch screens. We found that there is a large gap in recognition speed on mobile devices between recognizing simple shapes and more complex ones, suggesting that mobile sketch interface designers limit the complexity of their sketch domains. We also found that a low sampling rate on mobile devices can affect recognition accuracy of complex and curved shapes. Despite this, we found no evidence to suggest that using a finger as an input implement leads to a decrease in simple shape recognition accuracy. These results show that the same geometric shape recognizers developed for pen applications can be used in mobile applications, provided that developers keep shape domains simple and ensure that input sampling rate is kept as high as possible.

When asked to draw, most people are hesitant because they believe themselves unable to draw well. A human instructor can teach students how to draw by encouraging them to practice established drawing techniques and by providing personal and directed feedback to foster their artistic intuition and perception. This thesis describes the first methodology for a computer application to mimic a human instructor by providing direction and feedback to assist a student in drawing a human face from a photograph. Nine design principles were discovered and developed for providing such instruction, presenting reference media, giving corrective feedback, and receiving actions from the student. Face recognition is used to model the human face in a photograph so that sketch recognition can map a drawing to the model and evaluate it. New sketch recognition techniques and algorithms were created in order to perform sketch understanding on such subjective content. After two iterations of development and user studies for this methodology, the result is a computer application that can guide a person toward producing his/her own sketch of a human model in a reference photograph with step-bystep instruction and computer generated feedback.

One of the challenges students face in studying an East Asian (EA) language (e.g., Chinese, Japanese, and Korean) as a second language is mastering their selected language’s written component. This is especially true for students with native fluency of English and deficient written fluency of another EA language. In order to alleviate the steep learning curve inherent in the properties of EA languages’ complicated writing scripts, language instructors conventionally introduce various written techniques such as stroke order and direction to allow students to study writing scripts in a systematic fashion. Yet, despite the advantages gained from written technique instruction, the physical presence of the language instructor in conventional instruction is still highly desirable during the learning process; not only does it allow instructors to offer valuable real-time critique and feedback interaction on students’ writings, but it also allows instructors to correct students’ bad writing habits that would impede mastery of the written language if not caught early in the learning process. The current generation of computer-assisted language learning (CALL) applications specific to written EA languages have therefore strived to incorporate writing-capable modalities in order to allow students to emulate their studies outside the classroom setting. Several factors such as constrained writing styles, and weak feedback and assessment capabilities limit these existing applications and their employed techniques from closely mimicking the benefits that language instructors continue to offer. In this thesis, I describe my geometric-based sketch recognition approach to several writing scripts in the EA languages while addressing the issues that plague existing CALL applications and the handwriting recognition techniques that they utilize. The approach takes advantage of A Language to Describe, Display, and Editing in Sketch Recognition (LADDER) framework to provide users with valuable feedback and assessment that not only recognizes the visual correctness of students’ written EA Language writings, but also critiques the technical correctness of their stroke order and direction. Furthermore, my approach provides recognition independent of writing style that allows students to learn with natural writing through size- and amount-independence, thus bridging the gap between beginner applications that only recognize single-square input and expert tools that lack written technique critique.

We present a novel method for building 3D models from a user sketch. Given a 2D sketch as input, the approach aligns and deforms a chosen 3D template model to match the sketch. This is guided by a set of user-specified correspondences and an algorithm that deforms the 3D model to match the sketched profile. Our primary contribution is related to fitting the 3D deformable geometry to the 2D user sketch. We demonstrate our technique on several examples.

Kurybinis darbas, tai Jonathan'o Swift'o "Guliverio kelionių" vizuali interpretacija: scenografijos maketai ir kostiumų eskizai. Spektaklis skirtas vaikams, todėl pasirinkau kurti scenografiją Swift'o aprašytoms milžinų ir liliputų karalystėms. Darbą sudaro keturi scenovaizdžio maketai ir žaidimo principu pateikiami kostiumų ir scenovaizio eskizai. / This creative work, by Jonathan Swift "Gulliver's travels", is a visual interpretation - scenography models and costume sketches. Performance is dedicated for children, therefore i choose to make scenography for Swift's described kingdoms of giants and liliputians. Work consists of four models of scenery and sketches of costume and scenery, presented according to game principle.

Sketch recognition is an active research field, with the goal to automatically recognize hand-drawn diagrams by a computer. The technology enables people to freely interact with digital devices like tablet PCs, Wacoms, and multi-touch screens. These devices are easy to use and have become very popular in market. However, they are still quite costly and need more time to be integrated into existing systems. For example, handwriting recognition systems, while gaining in accuracy and capability, still must rely on users using tablet-PCs to sketch on. As computers get smaller, and smart-phones become more common, our vision is to allow people to sketch using normal pencil and paper and to provide a simple microphone, such as one from their smart-phone, to interpret their writings. Since the only device we need is a single simple microphone, the scope of our work is not limited to common mobile devices, but also can be integrated into many other small devices, such as a ring. In this thesis, we thoroughly investigate this new area, which we call acoustic based sketch recognition, and evaluate the possibilities of using it as a new interaction technique. We focus specifically on building a recognition engine for acoustic sketch recognition. We first propose a dynamic time wrapping algorithm for recognizing isolated sketch sounds using MFCC(Mel-Frequency Cesptral Coefficients). After analyzing its performance limitations, we propose improved dynamic time wrapping algorithms which work on a hybrid basis, using both MFCC and four global features including skewness, kurtosis, curviness and peak location. The proposed approaches provide both robustness and decreased computational cost. Finally, we evaluate our algorithms using acoustic data collected by the participants using a device's built-in microphone. Using our improved algorithm we were able to achieve an accuracy of 90% for a 10 digit gesture set, 87% accuracy for the 26 English characters and over 95% accuracy for a set of seven commonly used gestures.

We present a novel method for building 3D models from a user sketch. Given a 2D sketch as input, the approach aligns and deforms a chosen 3D template model to match the sketch. This is guided by a set of user-specified correspondences and an algorithm that deforms the 3D model to match the sketched profile. Our primary contribution is related to fitting the 3D deformable geometry to the 2D user sketch. We demonstrate our technique on several examples.

Nigel (Henry) Butterley (b. 1935) is recognised as one of Australia??s foremost contemporary composers. His works span most compositional genres. By making a case for the value of sketch study in the process of musical analysis, the principal purpose of this thesis is to augment understanding of Butterley??s music and in particular, his compositional processes and procedures through the various stages of the genesis of a composition, from the sketch to final score. Butterley??s string quartets, composed between the years 1965 to 2001 provide the basis for this study; these works are contextualised and examined to illustrate his approach to composition in microcosm and also his individual style within the genre of string quartet writing. This study focuses on the examination of preliminary sketches, drafts and holographs, as well as the scores of the completed works. Initially, analysis is based on preliminary sketches; this will be augmented by a formal analysis of the completed works. Traditionally, formal analysis deals with the final product, something that has been created, and in a sense, views a work retrospectively. Sketch study, in contrast, examines the work as it is being created and is concerned with the attendant compositional issues and choices available to the composer and the processes followed as he or she creates the composition. The current work will identify significant common features in all the string quartets, and will trace Butterley??s compositional trajectory through these works demonstrating that individual characteristics of Butterley??s style, emergent as early as 1965, continued to be utilised in 1995 and remain present in the Bagatelle of 2001. That these characteristics remain present in a minut?? is significant, in that the Bagatelle may be seen as a microcosm of the writing style evident in his larger works. This thesis will demonstrate that sketch study and formal analysis may interact in order to provide a more comprehensive interpretation of a composer??s work and enrich the understanding and appreciation of the compositional process and the final product, ultimately impacting on the realisation of a composer??s work through performance.

Esta pesquisa tem como objetivo, estabelecer um conjunto de diretrizes que facilitem a geração e a exploração de ideias, e a partir do conceito de esboço, traçar relações com o brinquedo, inserindo-as nas etapas de concepção do Design de Jogos. Para a elaboração dessas orientações, foram abordados cinco tópicos: o processo de desenvolvimento de jogos, a experiência do usuário nos jogos digitais, o processo criativo nos jogos, a resolução de problemas no Design, o brinquedo como atividade exploratória e precursora de jogos, bem como os tipos e formas encontrados nas atividades lúdicas. A pesquisa, então, relaciona as propriedades dos esboços e as propriedades dos brinquedos, para então estabelecer diretrizes para as fases conceituais do Design de Jogos bem como descreve uma série de orientações de projeto de jogos, baseadas nessas diretrizes. O relatório apresenta a aplicação das orientações na conceitualização de um jogo digital. O trabalho foi executado a partir de uma pesquisa bibliográfica, utilizando-se de documentação indireta, através de fontes secundárias e a aplicação das diretrizes desenvolvidas, na elaboração do conceito de um jogo. E como resultado dessa pesquisa, verificou-se que é possível agregar atividades geradoras de alternativas nas etapas preliminares do processo de desenvolvimento de jogos. / This research aims to establish a set of guidelines that facilitate the generation and exploration of ideas, and from the concept of the activity of sketch, establish parallels with the play, inserting them in the Design stages of game development. To elaborate the guidelines, were addressed five topics: the process of game development, user experience in digital games, the creative process in games, solving Design problems, the toy as exploratory activity and precursor to games as well as the types and forms found in recreational activities. The study then lists the properties of the sketches and the properties of the toys, and then show methodological guidelines for the conceptual stages of Game Design and describes a series of procedures for game Design, based on the guidelines. The report then presents the application of the guidelines in the conceptualization of a digital game. The methodology used in this study was the literature search, using indirect documentation, through secondary sources and application of guidelines developed in the elaboration of the concept of a game. And as a result of this research, it was found that it is possible to add alternative generating activities in the preliminary stages of the game development process.