1,470 research outputs found
Intelligent classification of sketch strokes
This paper presents an intelligent method for classifying pen strokes in an on-line sketching system. The method, based on adaptive threshold and fuzzy knowledge with respect to curve's linearity and convexity, can identify sketch strokes (curves) into lines, circles, arcs, ellipses, elliptical arcs, loop lines, spring lines and free-form B-spline curves. The proposed method has proven to be fast, suitable for real-time classification and identification
A Paradigm for Promoting Visual Synthesis through Freehand Sketching
Research (Fish, 2004) suggests that everybody should be taught how to freehand sketch and utilise it as a tool for supporting the visualising instinct. A fundamental shift in philosophy of the technology education system in Ireland towards design driven subjects brought with it a need to develop practising teacher’s technological capabilities. This paper is concerned with the exploration and development of freehand sketching as a support tool for visual synthesis and creative discovery during design driven activities. The fundamental hypothesis tested was whether a set of empirically derived activities ranging from observation to imagination, improved the ability of students with novice sketching ability to develop, manipulate and synthesise graphical libraries through the medium of freehand sketching. 124 students of an Initial Technology Teacher Education programme participated in a journey through the activities as part of a third year undergraduate Design and Communication Graphics module. The study was carried out over a four week period, it involved eight hours of classroom based instruction and the sketching ability of all students was measured pre and post-instruction. Results from the study reveal a statistically significant increase in student’s ability to freehand sketch with notable improvement in their fluency and ability to synthesise concepts and geometries. Overall, the novel and original activities have a notable effect on student’s ability to form, manipulate and synthesise visual information and communicate this through freehand sketching. The model presented has potential to be successively implemented by other teachers in a variety of educational settings and student populations
Sketch Beautification: Learning Part Beautification and Structure Refinement for Sketches of Man-made Objects
We present a novel freehand sketch beautification method, which takes as
input a freely drawn sketch of a man-made object and automatically beautifies
it both geometrically and structurally. Beautifying a sketch is challenging
because of its highly abstract and heavily diverse drawing manner. Existing
methods are usually confined to the distribution of their limited training
samples and thus cannot beautify freely drawn sketches with rich variations. To
address this challenge, we adopt a divide-and-combine strategy. Specifically,
we first parse an input sketch into semantic components, beautify individual
components by a learned part beautification module based on part-level implicit
manifolds, and then reassemble the beautified components through a structure
beautification module. With this strategy, our method can go beyond the
training samples and handle novel freehand sketches. We demonstrate the
effectiveness of our system with extensive experiments and a perceptive study.Comment: 13 figure
New method to find corner and tangent vertices in sketches using parametric cubic curves approximation
Some recent approaches have been presented as simple and highly accurate corner finders in the sketches including curves, which is useful to support natural human-computer interaction, but these in most cases do not consider tangent vertices (smooth points between two geometric entities, present in engineering models), what implies an important drawback in the field of design. In this article we present a robust approach based on the approximation to parametric cubic curves of the stroke for further radius function calculation in order to detect corner and tangent vertices. We have called our approach Tangent and Corner Vertices Detection (TCVD), and it works in the following way. First, corner vertices are obtained as minimum radius peaks in the discrete radius function, where radius is obtained from differences. Second, approximated piecewise parametric curves on the stroke are obtained and the analytic radius function is calculated. Then, curves are obtained from stretches of the stroke that have a small radius. Finally, the tangent vertices are found between straight lines and curves or between curves, where no corner vertices are previously located. The radius function to obtain curves is calculated from approximated piecewise curves, which is much more noise free than discrete radius calculation. Several tests have been carried out to compare our approach to that of the current best benchmarked, and the obtained results show that our approach achieves a significant accuracy even better finding corner vertices, and moreover, tangent vertices are detected with an Accuracy near to 92% and a False Positive Rate near to 2%.Spanish Ministry of Science and Education and the FEDER Funds, through CUESKETCH (Ref. DPI2007-66755-C02-01) and HYMAS projects (Ref. DPI2010-19457) partially supported this work.Albert Gil, FE.; GarcÃa Fernández-Pacheco, D.; Aleixos Borrás, MN. (2013). New method to find corner and tangent vertices in sketches using parametric cubic curves approximation. Pattern Recognition. 46(5):1433-1448. https://doi.org/10.1016/j.patcog.2012.11.006S1433144846
Deep Learning for Free-Hand Sketch: A Survey
Free-hand sketches are highly illustrative, and have been widely used by
humans to depict objects or stories from ancient times to the present. The
recent prevalence of touchscreen devices has made sketch creation a much easier
task than ever and consequently made sketch-oriented applications increasingly
popular. The progress of deep learning has immensely benefited free-hand sketch
research and applications. This paper presents a comprehensive survey of the
deep learning techniques oriented at free-hand sketch data, and the
applications that they enable. The main contents of this survey include: (i) A
discussion of the intrinsic traits and unique challenges of free-hand sketch,
to highlight the essential differences between sketch data and other data
modalities, e.g., natural photos. (ii) A review of the developments of
free-hand sketch research in the deep learning era, by surveying existing
datasets, research topics, and the state-of-the-art methods through a detailed
taxonomy and experimental evaluation. (iii) Promotion of future work via a
discussion of bottlenecks, open problems, and potential research directions for
the community.Comment: This paper is accepted by IEEE TPAM
A Paradigm for Promoting Visual Synthesis through Freehand Sketching
Research (Fish, 2004) suggests that everybody should be taught how to freehand sketch and utilise it as a tool for supporting the visualising instinct. A fundamental shift in philosophy of the technology education system in Ireland towards design driven subjects brought with it a need to
develop practising teacher’s technological capabilities. This paper is concerned with the exploration and development of freehand sketching as a support tool for visual synthesis and creative discovery during design driven activities
IDATER online conference: graphicacy and modelling 2010
IDATER online conference: graphicacy and modelling 201
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