A simple construction method for sequentially tidying up 2D online freehand sketches

This paper presents a novel constructive approach to sequentially tidying up 2D online freehand sketches for further 3D interpretation in a conceptual design system. Upon receiving a sketch stroke, the system first identifies it as a 2D primitive and then automatically infers its 2D geometric constraints related to previous 2D geometry (if any). Based on recognized 2D constraints, the identified geometry will be modified accordingly to meet its constraints. The modification is realized in one or two sequent geometric constructions in consistence with its degrees of freedom. This method can produce 2D configurations without iterative procedures to solve constraint equations. It is simple and easy to use for a real-time application. Several examples are tested and discussed

Building geometric models with hand-drawn sketches

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1998.Includes bibliographical references (p. 49-51).Architects work on drawings and models, not buildings. Today, in many architectural practices, drawings and models are produced in digital format using Computer-aided Design (CAD) tools. Unquestionably, digital media have changed the way in which many architects perform their day to day activities. But these changes have been limited to the more prosaic aspects of practice. To be sure, CAD systems have made the daily operations of many design offices more efficient; nevertheless, they have been of little use - and indeed are often a hindrance - in situations where the task at hand is more conjectural and speculative in nature, as it is during the early stages of a project. Well-intentioned efforts to insinuate CAD into these aspects of practice have only served to reveal the incongruities between the demands of designer and the configuration of the available tools. One of the chief attributes of design practice is that it is action performed at a distance through the agency of representations. This fundamental trait implies that we have to understand how computers help architects describe buildings if we are to understand how they might help architects design buildings. As obvious as this claim might seem, CAD programs can be almost universally characterized by a tacit denigration of visual representation. In this thesis, I examine properties of design drawings that make them useful to architects. I go on to describe a computer program that I have written that allows a designer to build geometric models using freehand sketches. This program illustrates that it is possible to design a software tool in a way that profits from, rather than negates, the power of visual representations.by Ewan E. Branda.M.S

The machine refinement of raw graphic data for translation into a low level data base for computer aided architectural design (CAAD).

It is argued that a significant feature which acts as a disincentive against the adoption of CAAD systems by small private architectural practices, is the awkwardness of communicating with computers when compared with traditional drawing board techniques. This consideration, although not perhaps the dominant feature, may be mitigated by the development of systems in which the onus of communicating is placed on the machine, through the medium of an architect's sketch plan drawing. In reaching this conclusion, a design morphology is suggested, in which the creative generation of building designs is set in the context of the development of a 'data-base' of information which completely and consistently describes the architect's hypothetical building solution. This thesis describes research carried out by the author between 1981 and 1984, and describes the theory, development and application of algorithms to interpret architect's sketch plan drawings, and hence permit the encoding of building geometries for CAAD applications programs

Ontologies and representation spaces for sketch map interpretation

In this paper, we present a systematic approach to sketch map interpretation. The method decomposes the elements of a sketch map into a hierarchy of categories, from the material sketch map level to the non-material representational sketch map level, and then interprets the sketch map using the five formal representation spaces that we develop. These spaces (set, graph, metric and Euclidean) provide a tiered formal representation based on standard mathematical structures. We take the view that a sketch map bears information about the physical world and systematises this using extensions of existing formal ontologies. The motivation for this work is the partially automatic extraction and integration of information from sketch maps. We propose a set of ontologies and methods as a first step in the direction of a formalisation of partially automatic extraction and integration of sketch map content. We also see this work as a contribution to spatial cognition, where researchers externalise spatial knowledge using sketch mapping. The paper concludes by working through an example that demonstrates the sketch map interpretation at different levels using the underlying method

The study of biographical trajectory of portuguese 12th century illuminated manuscript: LECCIONARIUM ALC. 433 from Alcobaça Collection held by The Biblioteca Nacional de Portugal

This thesis presents an interdisciplinary approach to a 12th century illuminated manuscript, a Leccionarium (Alc. 433), produced in Alcobaça Monastery which currently is being preserved at Biblioteca Nacional de Portugal in Lisbon. The aim of the work was to trace the biography of this illuminated manuscript, through the liturgical studies and to obtain the chronological timeline of the use of materials in Alcobaça scriptorium, through centuries. The representative folia of Alc. 433 were characterised with h-XRF, UV-Vis-NIR-FORS, and hyperspectral images. The result indicates that Alc. 433 was produced in the last quarter of the 12th century, followed by addition of some folia in 13th, 14th, and the beginning of 17th century. Materials identification revealed the use of different pigments in different periods: vermilion and minium (red), copper proteinate (bottle green), yellow lake pigments, azurite and lapis lazuli (blue). The PCA study of yellow lake dye reproduction indicates the use of turmeric yellow lake pigment in the initial core. Furthermore, the analysis of iron gall ink also shows that the initial core of Alc. 433 contains the similar ratios of elements with Alc. 11 (primitive manuscript of Alcobaça) thus proved the Alc. 433 was also the produced in the earliest period of the active year of Alcobaça scriptorium; RESUMO: O Estudo da Trajetória Biográfica do Manuscrito Português Iluminado do Século XII: Leccionarium Alc. 433 da Coleção de Alcobaça Detida pela Biblioteca Nacional de Portugal Esta tese apresenta uma abordagem interdisciplinar de um manuscrito iluminado do século XII, um Leccionarium (Alc. 433), produzido no Mosteiro de Alcobaça e que se encontra preservado na Biblioteca Nacional de Portugal em Lisboa. O objetivo deste trabalho foi traçar a biografia deste manuscrito iluminado, através do seu estudo litúrgico e obter a linha cronológica da utilização de materiais no scriptorium de Alcobaça, ao longo dos séculos. Os fólios mais representativos do Alc. 433 foram caracterizados h-XRF, UV-Vis-NIR-FORS e imagens hiperespectrais. O resultado indica que o Alc. 433 foi produzido no último quarto do século XII, e que foi enriquecido com a adição de fólios e/ou cadernos nos séculos XIII, XIV e inícios do século XVII. A identificação dos materiais revelou o uso de diferentes pigmentos em diferentes períodos: vermelhão e minium (vermelho), proteinato de cobre (verde garrafa), pigmento lago amarelo, azurite e lápis-lazúli (azul). O estudo PCA da reprodução do corante lago amarelo indica o uso de açafrão no núcleo inicial do pigmento. Além disso, a análise das tintas de escrita evidenciou uma analogia de composição da tinta ferrogálica utilizada no núcleo inicial do manuscrito Alc.433 e da tinta ferrogálica utilizada no texto do Alc.11 (outro manuscrito produzido nos primeiros anos do scriptorium de Alcobaça) o que comprovou assim que também o Alc. 433 foi produzido na mesma época, isto é, em torno de 1175

Experimental Object-Oriented Modelling

This thesis examines object-oriented modelling in experimental system development. Object-oriented modelling aims at representing concepts and phenomena of a problem domain in terms of classes and objects. Experimental system development seeks active experimentation in a system development project through, e.g., technical prototyping and active user involvement. We introduce and examine "experimental object-oriented modelling" as the intersection of these practices

Associating object names with descriptions of shape that distinguish possible from impossible objects.

Five experiments examine the proposal that object names are closely linked torepresentations of global, 3D shape by comparing memory for simple line drawings of structurally possible and impossible novel objects.Objects were rendered impossible through local edge violations to global coherence (cf. Schacter, Cooper, & Delaney, 1990) and supplementary observations confirmed that the sets of possible and impossible objects were matched for their distinctiveness. Employing a test of explicit recognition memory, Experiment 1 confirmed that the possible and impossible objects were equally memorable. Experiments 2–4 demonstrated that adults learn names (single-syllable non-words presented as count nouns, e.g., “This is a dax”) for possible objectsmore easily than for impossible objects, and an item-based analysis showed that this effect was unrelated to either the memorability or the distinctiveness of the individual objects. Experiment 3 indicated that the effects of object possibility on name learning were long term (spanning at least 2months), implying that the cognitive processes being revealed can support the learning of object names in everyday life. Experiment 5 demonstrated that hearing someone else name an object at presentation improves recognition memory for possible objects, but not for impossible objects. Taken together, the results indicate that object names are closely linked to the descriptions of global, 3D shape that can be derived for structurally possible objects but not for structurally impossible objects. In addition, the results challenge the view that object decision and explicit recognition necessarily draw on separate memory systems,with only the former being supported by these descriptions of global object shape. It seems that recognition also can be supported by these descriptions, provided the original encoding conditions encourage their derivation. Hearing an object named at encoding appears to be just such a condition. These observations are discussed in relation to the effects of naming in other visual tasks, and to the role of visual attention in object identification

Room for chaos? : authenticity and performance in undergraduate spatial design students’ accounts of ideational work

A thesis submitted to the University of Bedfordshire, in fulfilment of the requirements for the degree of Professional DoctorateThis study was prompted by my suspicion that spatial design undergraduates’ production of paper-based freehand sketches during design ideation was in decline. Seeking to find out why, I conducted video-recorded focused interviews with undergraduates from a range of UK spatial design degrees, during which we examined their sketchbook material and discussed their ideational activities (termed ‘ideational moves’). I subjected the data to a form of content analysis, but the outcomes appeared to contradict my initial premise whilst revealing that the interactions during the interviews between myself, the respondents and the sketchbook material (termed ‘discursive moves’) warranted examination. This persuaded me that the study’s focus should emerge through ‘evolved’ grounded theory rather than being stated a priori, which highlighted my presence in, and impact on, the data and prompted me to adopt a constructivist grounded theorising approach in combination with actor-network theory’s concepts of translation and circulating references. This study has thus been qualitative, relativist, iterative and multi-modal. Grounded theorising led to the identification of a number of categories and sub-categories of ideational move across the sample, and indicated that the respondents had used a ‘core’ of each. ‘Core’ categories comprised: making paper-based ideational moves, carrying out research and using photographic material. Several respondents also evidenced producing digital imagery and physical models. ‘Core’ sub-categories comprised using paper-based freehand perspective sketches, sketch diagrams and word-based approaches, plus supporting visuo-spatial research. Several respondents also evidenced producing paper-based freehand plan, section and elevation sketches, plus collage. Grounded theorising also revealed that each respondent had utilised a different combination of sub-categories, with different degrees of connectedness. I did not set out to evaluate the design outcomes showcased, but, as a spatial design academic and practitioner, I felt compelled to. This led to the tentative conclusion that respondents who added to the ‘core’ of categories and sub-categories and worked with greater connectedness appeared to produce more thoroughly-considered work, whilst those who forsook the ‘core’ and worked with less connectedness appeared to produce more unexpected results by allowing ‘…room for chaos…’: periods of confusion and surprise. Regarding the discursive moves, grounded theorising indicated that the sketchbook material tabled by each respondent during the study was not one fixed thing, but an abstraction using placing-for and directing-to techniques to focus attention on certain ideational moves and away from others. This made the sketchbook material a performance within the network of human and non-human actors who, in effect, co-constructed it as a temporary reality without necessarily realising this. Research into sketchbook material appears to regard it, once shared with others, as having the candour of a secret diary, and as eligible for formative and summative assessment because it documents design process authentically. My study, whilst not claiming generalisability, suggests that this view should be challenged. The new knowledge is now informing my future teaching practice and will, I hope, prompt other academics to investigate whether their own students manifest similar outcomes and, through this, contribute to wider discussions on the formative and summative assessment of undergraduate spatial design development activity

A simplified and novel technique to retrieve color images from hand-drawn sketch by human

With the increasing adoption of human-computer interaction, there is a growing trend of extracting the image through hand-drawn sketches by humans to find out correlated objects from the storage unit. A review of the existing system shows the dominant use of sophisticated and complex mechanisms where the focus is more on accuracy and less on system efficiency. Hence, this proposed system introduces a simplified extraction of the related image using an attribution clustering process and a cost-effective training scheme. The proposed method uses K-means clustering and bag-of-attributes to extract essential information from the sketch. The proposed system also introduces a unique indexing scheme that makes the retrieval process faster and results in retrieving the highest-ranked images. Implemented in MATLAB, the study outcome shows the proposed system offers better accuracy and processing time than the existing feature extraction technique