Development and evaluation of a digital tool for virtual reconstruction of historic Islamic geometric patterns

For the purpose of cultural heritage preservation, the task of recording and reconstructing visually complicated architectural geometrical patterns is facing many practical challenges. Existing traditional technologies rely heavily on the subjective nature of our perceptual power in understanding its complexity and depicting its color differences. This study explores one possible solution, through utilizing digital techniques for reconstructing detailed historical Islamic geometric patterns. Its main hypothesis is that digital techniques offer many advantages over the human eye in terms of recognizing subtle differences in light and color. The objective of the study is to design, test and evaluate an automatic visual tool for identifying deteriorated or incomplete archaeological Islamic geometrical patterns captured in digital images, and then restoring them digitally, for the purpose of producing accurate 2D reconstructed metric models. An experimental approach is used to develop, test and evaluate the specialized software. The goal of the experiment is to analyze the output reconstructed patterns for the purpose of evaluating the digital tool in respect to reliability and structural accuracy, from the point of view of the researcher in the context of historic preservation. The research encapsulates two approaches within its methodology; Qualitative approach is evident in the process of program design, algorithm selection, and evaluation. Quantitative approach is manifested through using mathematical knowledge of pattern generation to interpret available data and to simulate the rest based on it. The reconstruction process involves induction, deduction and analogy. The proposed method was proven to be successful in capturing the accurate structural geometry of the deteriorated straight-lines patterns generated based on the octagon-square basic grid. This research also concluded that it is possible to apply the same conceptual method to reconstruct all two-dimensional Islamic geometric patterns. Moreover, the same methodology can be applied to reconstruct many other pattern systems. The conceptual framework proposed by this study can serve as a platform for developing professional softwares related to historic documentation. Future research should be directed more towards developing artificial intelligence and pattern recognition techniques that have the ability to suplement human power in accomplishing difficult tasks

Algorithmic Comparison of "Shamsah" in Iranian Architecture, Carpet and Pottery

During various art periods of Iran, three art fields of pottery, architectural decorations and carpet weaving have had a significant contribution to the artistic trends of the Islamic period. The purpose of the present research was to explain and analyze the geometric patterns used in the Islamic artworks of pottery, architecture and carpet weaving and the influence of these three fields of art on each other. Other research objectives were also to examine the common features of above-mentioned fields of art in order to provide a schematic model based on their artistic nature. The main question of the present research were as follows: 1.What are the common features of Shamsah, in terms of geometric shape, in the three above-mentioned fields of art, given their different historical intervals and art periods? 2. How is it possible to achieve similar shapes through changing the geometrical parameters in the mathematical algorithm of these Shamsah? This research was conducted using a comparative-analytical approach. Data were collected using desk studies – due to the research literature – and field studies – because of observing and taking pictures of some decorations in three above-mentioned fields of art. Finally, computer simulation was used to do data analysis. The results of this study indicated that the principles of composition of geometric patterns in the three studied fields of art were based on the order, arrangement and organization of motifs to achieve a coherent format. &nbsp

Contemplative Space: Design for Generative Parametric Tessellations Applied to a Shell Structure

This thesis focuses on surface articulation of a shell structure constructed through a generative, parametric, modular design process. The shell form uses vault topology that adapts to varying site conditions such as topography and shape and that serves as contemplative space. Contemplative and aesthetic qualities have been achieved by analyzing aspects of spatial vernacular muqarnas and emulating aspects of their geometry within new surface ornament. By abstracting muqarnas, and exploring aniconic character informed by both vernacular precedent and contemporary parametric design methods, the design offers a specialized new interpretation of this historical type of ornament. The design proposes an expandable master system. Two strategies based on this system are illustrated, both organized with similar components: columns (load-bearing modules) and bridges (modules for covering spans). Different behaviours are exhibited: first, symmetrical and homogeneous form and, second, non-symmetrical and heterogeneous form. The second layer of this complex system uses the topology of a vault system. A decoration system proposed for articulating interior-oriented surfaces is based on algorithmic geometry. This system offers two different characters, first inspired by muqarnas as a specific vernacular ornament, primarily from traditional Persian architecture, and second as a non-cultural, neutral ornament originating from computational design and achieved by deformation of mesh division. Software tool use is illustrated, demonstrating how scripted Grasshopper software components hosting custom C# code passages are used within a multi-layer design process. Research informing this design focuses on historical and contemporary architecture. Contemporary precedents, “Arabesque Wall,” by Benjamin Dillenburger and Michael Hansmeyer, and “La Voûte de LeFevre” by Brandon Clifford and Wes McGee are described. An analysis of these precedents explores how emerging digital technologies informed by history, can create a new design ecology and culture. Additional discussion considers cultural and phenomenological observations and aesthetics of the design in its physical and psychological aspects, considered in contexts that range from topology of the form to visual perception of the internal “contemplative space.” This investigation indicates points of contact between arabesque art as vernacular ornament and contemporary, computer-based art. Computational and parametric design is considered with regards to its effect on contemporary design culture. Parametric strategies, software, and C# coding used in the thesis are illustrated. The spatial ornament known as muqarnas is analyzed as one example of algorithmic ornament, illustrated through a contemporary “art of the knot” designed using parametric tools. In the last part of the research, features of the vault system are demonstrated historically and through individual examples of each kind. In parallel, contemporary shell structure and form optimization by means of computational simulation and morphogenesis are investigated. The parametric system developed in the thesis design provides an opportunity to design a complex geometrical system that can be applied to shell-like envelopes. Design studies included within the thesis feature free-standing shelters capable of hosting a variety of public or private activities. Emphasizing visual and decorative qualities, visualizations of the applied design system are developed and positioned within sites in different locations

Matching Islamic patterns in Kufic images

In this study, we address the problem of matching patterns in Kufic calligraphy images. Being used as a decorative element, Kufic images have been designed in a way that makes it difficult to be read by non-experts. Therefore, available methods for handwriting recognition are not easily applicable to the recognition of Kufic patterns. In this study, we propose two new methods for Kufic pattern matching. The first method approximates the contours of connected components into lines and then utilizes chain code representation. Sequence matching techniques with a penalty for gaps are exploited for handling the variations between different instances of sub-patterns. In the second method, skeletons of connected components are represented as a graph where junction and end points are considered as nodes. Graph isomorphism techniques are then relaxed for partial graph matching. Methods are evaluated over a collection of 270 square Kufic images with 8,941 sub-patterns. Experimental results indicate that, besides retrieval and indexing of known patterns, our method also allows the discovery of new patterns. © 2015, Springer-Verlag London

3D Mapping of Islamic Geometric Motifs

In this thesis a novel approach in generating 3D IGP is applied using shape grammar, an effective pattern generation method. The particular emphasis here is to generate the motifs (repeat unit) in 3D using parameterization, which can then be manipulated within 3D space to construct architectural structures. Three unique distinctive shape grammar algorithms were developed in 3D; Parameterized Shape Grammar (PSG), Auto-Parameterized Shape Grammar (APSG) and Volumetric Shell Shape Grammar (VSSG). Firstly, the PSG generates the motifs in 3D. It allows one to use a single changeable regular 3D polygon, and forms a motif by given grammar rules including, Euclidean transformations and Boolean operations. Next, APSG was used to construct the architectural structures that manipulates the motif by automating the grammar rules. The APSG forms a wall, a column, a self-similarity star and a dome, the main features of Islamic architecture. However, applying Euclidean transformations to create non-Euclidean surfaces resulted in gaps and or overlaps which does not form a perfect tessellation. This is improved upon by the VSSM, which integrates two key methods, shell mapping and coherent point drift, to map an aesthetically accurate 3D IGM on a given surface. This work has successfully presented methods for creating complex intricate 3D Islamic Geometric Motifs (IGM), and provided an efficient mapping technique to form visually appealing decorated structures.Partially funded by the Centre of Visual Computing (CVC

The evolution of muqarnas in Iran from pre-seljuk to ilkhanid period

Muqarnas has always been one of the most complex decorative elements of worlds monumental architecture. In muqarnas, niche–like components are combined together and arranged in successive tiers to produce a three–dimensional geometric shape, enclosing and embellishing features such as ceiling, soffit, portal, and vault. This unique structure has been intensely studied from various aspects by many scholars. Nevertheless, there is still lack of clarification about the structures origin and path of evolution. There are some theories indicating that the structure is originated from squinches in Iran, but no further explanation is provided to fill the huge gap between the two, i.e. muqarnas and squinch, and to clarify the quality of the gradual development. This study assumes that the missing link between muqarnas and squinch should be sought in another undefined form in traditional architecture of Iran, named patkaneh. In this research, the main effort is to investigate the possibility of differentiating this ornament from muqarnas and to introduce it as a different structure, which is the missing link between squinch and muqarnas. This thesis employs a qualitative approach that strives to demonstrate the steps of gradual deformation of muqarnas from squinch by defining the characteristics of the linking ornament, using an inductive approach. For that, 20 critical samples of muqarnas and pseudo-muqarnas were selected out of a collection of 100 structures, by considering three main perspectives, i.e. chronology, form and structure, and construction techniques, with specific attention to the structure?s constituent elements and number of tiers as an indicator of the ornaments complexity. The differences and similarities identified among the selected samples lead to demonstrating the structures path of evolution. The results show there is another type (patkaneh) of ornamental structures with different characteristics in comparison with muqarnas. Therefore, this study contributes patkaneh as the connecting link between muqarnas and squinch, which is misinterpreted in many texts as muqarnas and thereafter shall be appropriately referred to none other than patkaneh

Segmentation based Ottoman text and matching based Kufic image analysis

Ankara : The Department of Computer Engineering and the Graduate School of Engineering and Science of Bilkent University, 2013.Thesis (Master's) -- Bilkent University, 2013.Includes bibliographical references leaves 80-88.Large archives of historical documents attract many researchers from all around the world. The increasing demand to access those archives makes automatic retrieval and recognition of historical documents crucial. Ottoman archives are one of the largest collections of historical documents. Although Ottoman is not a currently spoken language, many researchers from all around the world are interested in accessing the archived material. This thesis proposes two Ottoman document analysis studies; first one is a crucial pre-processing task for retrieval and recognition which is segmentation of documents. Second one is a more specific retrieval and recognition problem which aims matching Islamic patterns is Kufic images. For the first segmentation task, layout, line and word segmentation is studied. Layout segmentation is obtained via Log-Gabor filtering. Four different algorithms are proposed for line segmentation and finally a simple morphological method is preferred for word segmentation. Datasets are constructed with documents from both Ottoman and other languages (English, Greek and Bangla) to test the script-independency of the methods. Experiments show that our segmentation steps give satisfactory results. The second task aims to detect Islamic patterns in Kufic images. The sub-patterns are considered as basic units and matching is used for the analysis. Graphs are preferred to represent subpatterns where graph and sub-graph isomorphism are used for matching them. Kufic images are analyzed in three different ways. Given a query pattern, all the instances of the query can be found through retrieval. Going further, through known patterns images can be automatically labeled in the entire dataset. Finally, patterns that repeat inside an image can be automatically discovered. As there is no existing Kufic dataset, a new one is constructed by collecting images from the Internet and promising results are obtained on this dataset.Adıgüzel, HandeM.S