A profile-driven sketching interface for pen-and-paper sketches

This research is funded by the University of Malta under the research grant R30 31330 and is part of the project Innovative ‘Early Design’ Product Prototyping (InPro).Sketching interface tools are developed to allow designers to benefit from the powerful computational tools avail- able in computer aided design systems. However, despite the number of sketching tools such as PDAs and Tablet PCs available on market, designers typically create a number of initial conceptual ideas using paper-based sketches and scribbles such that these tools remain inaccessible to designers in the early design stages. In this paper we describe a profile-driven, paper-based sketching interface which infers the 3D geometry of objects drawn by designers using the traditional pen and paper sketching. We show that by making full use of the shape information present in the scribbled drawing, it is possible to obtain a paper-based sketching interface that retains the simplicity of the early- stage design drawings while allowing for the modeling of a variety of object shapes.peer-reviewe

Paper-based scribble simplification : where do we stand?

This research is funded by the University of Malta under theresearch grant IED 73-529 and is part of the project Innovative ‘Early Design’ Product Prototyping (InPro).This paper presents a formal evaluation of the paper-based scribble simplification algorithm described in [BCFB07] and [BCFB08]. A comparative analysis of different aspects of the algorithm with other algorithms described in the literature such as Sparse Pixel Vectorization, spatial moving average filtering and Principal Component Analysis is performed, hence establishing the qualities of this paper-based scribble simplification algorithm. To quantify the performance of the algorithm, performance measures established in the literature, such as the Pixel Recovery Index are used when suitable. However, since there exists no quantitative measure which measures scribble simplification, this paper proposes a new methodology with which scribble simplification may be quantitatively assessed. Through the evaluation described in this paper, we will be able to determine remaining difficulties in the interpretation of paper-based scribbles and hence identify future research areas.peer-reviewe

Adaptation of Brensen's thresholding algorithm for sketched line drawings

Image binarisation is one of the first image processing techniques within a sketched line drawing interpretation system. In order to achieve an automated system, it is necessary to have a single algorithm which may be used for all image types. This is difficult to obtain if the parameters required by an algorithm are set manually, however, the adaptive evaluation of parameters form image properties is a step towards this goal. This paper discusses the methods by which the parameters required for Brensen's Algorithm may be evaluated adaptively form the image properties.peer-reviewe

A new sketch based interface using the gray-level co-occurrence matrix for perceptual simplification of paper based scribbles

The sketching activity has an important role in conceptual design and a variety of tools exist which help designers to facilitate the generation of 3D models form sketched drawings. This paper describes a new sketch-to-3D tool, which uses annotations to aid the interpretation of the drawing. Over-traced lines present in the designer’s scrib- bles provide an interpretation challenge, which must be resolved in order to obtain 3D models from these sketches. Perceptual grouping techniques used to interpret such images require that the drawing is represented as vectors. These are generally obtained through thinning or edge detection. However, we show that processing scribbles using these techniques result in a large number of vectors which do not provide a faithful representation of the drawing. This paper investigates the use of the co-occurrence matrix to perceptually simplify these drawings, thus obtaining a smaller number of vectors which describe the drawing more faithfully.peer-reviewe

Line tracking algorithm for scribbled drawings

This paper describes a line tracking algorithm that may be used to extract lines from paper based scribbles. The proposed algorithm improves the performance of existing sparse-pixel line tracking techniques that are used in vectorization by introducing perceptual saliency and Kalman filtering concepts to the line tracking. Furthermore, an adaptive sampling size is used such that it is possible to adjust the size of the tracking step to reflect the stroke curvature.peer-reviewe

Scribbles to vectors : preparation of scribble drawings for CAD interpretation

This paper describes the work carried out on off-line paper based scribbles such that they can be incorporated into a sketch-based interface without forcing designers to change their natural drawing habits. In this work, the scribbled drawings are converted into a vectorial format which can be recognized by a CAD system. This is achieved by using pattern analysis techniques, namely the Gabor filter to simplify the scribbled drawing. Vector line are then extracted from the resulting drawing by means of Kalman filtering.peer-reviewe

A cameraphone-based approach for the generation of 3D models from paper sketches

Parts of the research work disclosed in this paper are subject to a pending patent application number 2130.Due to the advantages it offers, a sketch-based user-interface (UI) has been utilised in various domains, such as 3D modelling, 'graphical user-interface' design, 3D animation of cartoon characters, etc. However, its benefits have not yet been adequately exploited with those of a mobile phone, despite that the latter is nowadays a widely used wireless handheld device for mobile communication. Given this scenario, this paper discloses a novel approach of using a paper sketch-based UI, which combines the benefits of paper sketching and those of a cameraphone (a mobile phone with an integrated camera), in the domain of early form design modelling. More specifically, the framework disclosed and evaluated in this paper, enables users to remotely obtain visual representations of 3D geometric models from freehand sketches by combining the portability of paper with that of cameraphones. Based on this framework, a prototype tool has been implemented and evaluated. Despite the limitations of the current prototype tool, the evaluation results of the framework s underlying concepts and of the prototype tool collectively indicate that the idea disclosed in this paper contributes in providing users with a mobile sketch-based interface, which can also be used in other domains, beyond early form design modelling.peer-reviewe

Image binarisation using the extended Kalman filter

This work has been mainly supported by Grant 73604 of the University of Malta.Form design is frequently carried out through paper sketches of the designer’s mental model of an object. To improve the time it takes from solution concept to production it would therefore be beneficial if paperbased sketches can be automatically interpreted for importation into three-dimensional geometric computer aided design (CAD) systems. This however requires image pre-processing before initiating the automated interpretation of the drawing. This paper proposes a novel application of the Extended Kalman Filter to guide the binarisation process, thus achieving suitable and automatic classification between image foreground and background.peer-reviewe

Desempenho Neuropsicológico e indicadores de frequência, duração e tempo da sessão do exercício físico

Objective. Physical Exercise (PE) is related to cerebral structures and cognitive functioning. Nevertheless, PE indicators of frequency, duration, intensity and neuropsychological processes are unknown. The goal was to study the relationship and the possible differences between executive functions (EF) and PE indicators (frequency, duration and time PE is being practiced). Method. We selected an intentional sample of thirty physically active subjects, paired by sex (Mage = 22.9, SD = 8.5). We used the whole assessment of Executive Functions and Frontal Lobes Battery (BANFE). Results. Neuropsychological performance was related to the PE frequency in tasks that assess inhibitory control, monitoring of limits and rules, visual-spatial working memory and predicting in reversal and progressive order actions. The duration and time of training showed relationship with planning and inhibition control. The participants who exercise more than six times a week showed a better performance and less number of inhibition control mistakes. Neuropsychological performance dependent on indicators and type of PE are not distinguished. Conclusion. The hypothesis is confirmed. There is a relationship between PE and neuropsychological processes with possible scientific, educational and clinical implications.Objetivo. El ejercicio físico (EF) se relaciona con estructuras cerebrales y funcionamiento cognitivo; sin embargo, se desconocen indicadores de frecuencia, duración e intensidad del EF asociados a procesos neuropsicológicos. Estudiar la relación y las posibles diferencias entre las funciones ejecutivas (FE) y los indicadores del EF (frecuencia, duración y tiempo que lleva practicando EF). Método. Se seleccionó una muestra intencional de treinta sujetos físicamente activos, pareados por sexo (Medad = 22.9, DE = 8.5). Se aplicó la totalidad de la Batería de Funciones Ejecutivas y Lóbulos Frontales (Banfe). Resultados. El desempeño neuropsicológico se relacionó con la frecuencia del EF en tareas que evalúan capacidades de control inhibitorio, seguimiento de límites y normas, memoria de trabajo visoespacial y anticipación de acciones de orden progresivo y regresivo. La duración y el tiempo de entrenamiento presentaron relación con la planeación, respeto por los límites y la inhibición. Aquellos participantes que se ejercitan más de seis veces por semana presentaron mejor desempeño en los aciertos y menor número de errores en el control inhibitorio. No se diferencia el desempeño neuropsicológico en función a indicadores y tipo de EF. Conclusión. Se confirma la hipótesis acerca de que el EF se asocia con procesos neuropsicológicos. Se abren posibles implicaciones científicas, educativas y clínicas.Escopo. O Exercício Físico (EF) está relacionado com estruturas cerebrais e funcionamento cognitivo. Porém são desconhecidos indicadores de frequência, duração e intensidade de EF associados aos processos neuropsicológicos. Estudar a relação e as possíveis diferenças entre as Funções Executivas (FE) e indicadores do EF (Frequência, Duração e Tempo que leva praticando EF). Metodologia. Foi selecionada uma amostra intencional de trinta sujeitos ativamente físicos, pareados por sexo (Midade= 22.9, DE= 8.5). Foi aplicada a totalidade da Bateria de Funções Executivas e Lóbulos Frontais (BANFE). Resultados. O desempenho neuropsicológico esteve relacionado com a Frequência do EF em tarefas que avaliam capacidades de controle inibitório, seguimento de limites e normas, memória de trabalho vioespacial, e antecipação de ações de ordem progressiva e regressiva. A duração e o tempo de treinamento apresentaram relação com o planejamento, respeito pelos limites e a inibição. Aqueles participantes que se exercitaram mais de seis vezes por semana apresentaram melhor desempenho nos sucessos e menor número de erros no controle inibitório. Não houve diferença no desempenho neuropsicológico em função a indicadores e tipo de EF. Conclusão. Foi confirmada a hipótese de que o EF está associado com processos neuropsicológicos. Foram abertas possíveis implicações científicas, educativas e clínicas