تمثيل الإطار الخارجي للكلمات العربية بكفاءة من خلال الدمج بين نموذج الكنتور النشط وتحديد ونقاط الزوايا

Graphical curves and surfaces fitting are hot areas of research studies and application, such as artistic applications, analysis applications and encoding purposes. Outline capture of digital word images is important in most of the desktop publishing systems. The shapes of the characters are stored in the computer memory in terms of their outlines, and the outlines are expressed as Bezier curves. Existing methods for Arabic font outline description suffer from low fitting accuracy and efficiency. In our research, we developed a new method for outlining shapes using Bezier curves with minimal set of curve points. A distinguishing characteristic of our method is that it combines the active contour method (snake) with corner detection to achieve an initial set of points that is as close to the shape's boundaries as possible. The method links these points (snake + corner) into a compound Bezier curve, and iteratively improves the fitting of the curve over the actual boundaries of the shape. We implemented and tested our method using MATLAB. Test cases included various levels of shape complexity varying from simple, moderate, and high complexity depending on factors, such as: boundary concavities, number of corners. Results show that our method achieved average 86% of accuracy when measured relative to true shape boundary. When compared to other similar methods (Masood & Sarfraz, 2009; Sarfraz & Khan, 2002; Ferdous A Sohel, Karmakar, Dooley, & Bennamoun, 2010), our method performed comparatively well. Keywords: Bezier curves, shape descriptor, curvature, corner points, control points, Active Contour Model.تعتبر المنحنيات والأسطح الرسومية موضوعاً هاماً في الدراسات البحثية وفي التطبيقات البرمجية مثل التطبيقات الفنية، وتطبيقات تحليل وترميز البيانات. ويعتبر تخطيط الحدود الخارجية للكلمات عملية أساسية في غالبية تطبيقات النشر المكتبي. في هذه التطبيقات تخزن أشكال الأحرف في الذاكرة من حيث خطوطها الخارجية، وتمثل الخطوط الخارجية على هيئة منحنيات Bezier. الطرق المستخدمة حالياً لتحديد الخطوط الخارجية للكلمات العربية تنقصها دقة وكفاءة الملاءمة ما بين الحدود الحقيقية والمنحنى الرسومي الذي تقوم بتشكيله. في هذا البحث قمنا بتطوير طريقة جديدة لتخطيط الحدود الخارجية للكلمات تعتمد على منحنيات Bezier بمجموعة أقل من المنحنيات الجزئية. تتميز طريقتنا بخاصية مميزة وهي الدمج بين آلية لاستشعار الزوايا مع آلية نموذج الكنتور النشط (الأفعى). يتم الدمج بين نقاط الزوايا ونقاط الأفعى لتشكيل مجموعة موحدة من النقاط المبدئية قريبة قدر الإمكان من الحدود الحقيقية للشكل المراد تحديده. يتشكل منحنى Bezier من هذه المجموعة المدمجة، وتتم عملية تدريجية على دورات لملاءمة المنحنى على الحدود الحقيقية للشكل. قام الباحث بتنفيذ وتجربة الطريقة الجديدة باستخدام برنامج MATLAB. وتم اختيار أشكال رسومية كعينات اختبار تتصف بمستويات متباينة من التعقيد تتراوح ما بين بسيط إلى متوسط إلى عالي التعقيد على أساس عوامل مثل تقعرات الحدود، عدد نقاط الزوايا، الفتحات الداخلية، إلخ. وقد أظهرت نتائج الاختبار أن طريقتنا الجديدة حققت دقة في الملائمة تصل نسبتها إلى 86% مقارنة بالحدود الحقيقية للشكل المستهدف. وكذلك فقد كان أداء طريقتنا جيداً بالمقارنة مع طرق أخرى مماثلة

Oriental fonts auto boldness.

by Lo I Fan.Thesis (M.Phil.)--Chinese University of Hong Kong, 1994.Includes bibliographical references.Chapter Chapter 1: --- IntroductionChapter 1.1 --- The Evolution of Fonts --- p.1Chapter 1.2 --- Bitmap Fonts --- p.2Chapter 1.3 --- Outline FontsChapter 1.3.1 --- Arc and Vector Form --- p.4Chapter 1.3.2 --- Spline Form --- p.4Chapter 1.3.3 --- Pros and Cons of Outline Fonts --- p.8Chapter 1.4 --- Examples of Outline FontsChapter 1.4.1 --- Adobe's PostScript --- p.9Chapter 1.4.2 --- Apple's and Microsoft TrueTypeChapter 1.4.2.1 --- Outline Representation --- p.10Chapter 1.4.2.2 --- Rasterisation --- p.12Chapter 1.4.2.3 --- Hinting --- p.13Chapter 1.5 --- Bold FontsChapter 1.5.1 --- Definition of Bold --- p.15Chapter 1.5.2 --- Definition of Auto B oldness --- p.16Chapter 1.5.3 --- Auto Boldness by Double Printing --- p.17Chapter 1.5.4 --- Auto Boldness by Multi-Master Technique --- p.18Chapter 1.6 --- Chinese FontsChapter 1.6.1 --- Chinese Character Sets --- p.19Chapter 1.6.2 --- The Subtleties of Chinese Fonts Auto Boldness --- p.21Chapter 1.7 --- Project Objective --- p.23Chapter 1.8 --- Goals --- p.23Chapter Chapter 2: --- Main Ideas of Chinese Font Auto BoldnessChapter 2.1 --- Prototype of Auto Boldness Driver --- p.24Chapter 2.2 --- Design Features of the Prototype Auto Boldness Driver --- p.25Chapter 2.3 --- Data Structure and Algorithm of Auto BoldnessChapter 2.3.1 --- Data Structure of TrueType Character Outline --- p.27Chapter 2.3.2 --- Algorithm of Auto Boldness --- p.28Chapter 2.3.3 --- Algorithm Description --- p.29Chapter 2.4 --- Component Font Auto Boldness --- p.35Chapter Chapter 3: --- Language of Auto BoldnessChapter 3.1 --- Enhancements of TrueType Engine to support Auto Boldness --- p.36Chapter 3.2 --- Symmetric Bold Instruction --- p.38Chapter 3.3 --- Rotate Bold Instruction --- p.47Chapter 3.4 --- Asymmetric B old Instruction --- p.50Chapter 3.5 --- Comparison of Bold Instructions --- p.54Chapter 3.6 --- Serif Accommodation Instruction --- p.55Chapter Chapter 4: --- Shape Parsing and Auto Bold Code GenerationChapter 4.1 --- Compilation Process and Auto Boldness --- p.62Chapter 4.2 --- Shape Lexical Analyzer --- p.64Chapter 4.3 --- Shape Token Attributes EvaluationChapter 4.3.1 --- line Token --- p.66Chapter 4.3.2 --- bezier2 Token --- p.67Chapter 4.3.3 --- sharp Token --- p.70Chapter 4.3.4 --- concave Token --- p.75Chapter 4.3.5 --- convex Token --- p.75Chapter 4.4 --- Scope of Shape Parsing --- p.76Chapter 4.5 --- Shape Parsing Mechanism --- p.77Chapter 4.6 --- Model Grammar RulesChapter 4.6.1 --- Grammar Rule Format --- p.81Chapter 4.6.2 --- Grammar Rule Item --- p.82Chapter 4.6.3 --- Grammar Rule Assignment --- p.83Chapter 4.6.4 --- Grammar Rule Condition --- p.83Chapter 4.7 --- Auto Boldness Code Generation --- p.84Chapter 4.8 --- Program Methodology of Prototype Auto Boldness Driver --- p.86Chapter Chapter 5: --- ConclusionsChapter 5.1 --- Work Achieved --- p.87Chapter 5.2 --- The Pros and Cons of Auto Boldness Algorithm --- p.88Chapter 5.3 --- Bold Quality Assessments --- p.91Chapter 5.3 --- Future Directions --- p.93ReferencesAppendix OneAppendix Tw

A new approach to the generation of Gray scale Chinese fonts.

by Poon Chi-cheung.Thesis (M.Phil.)--Chinese University of Hong Kong, 1993.Includes bibliographical references (leaves 82-84).AbstractAcknowledgmentsPrefaceChapter Chapter 1: --- Font Systems --- p.1Representations of Character Images --- p.1Characteristics of Chinese Font System --- p.3Large Character Set --- p.3Condensed Strokes --- p.4Low Repetition Rate --- p.5WYSIWYG (What You See Is What You Get) --- p.6Chapter Chapter 2: --- Human Visual System and Gray Scale Font --- p.9Human Visual System --- p.9Physiology --- p.9Spatial Frequencies --- p.10How much resolution is enough --- p.11Screen and Printer --- p.12Raster Display Devices --- p.13Printer --- p.14Resolution --- p.15Gray Scale Font --- p.15Generation of Gray Scale Font --- p.18Chapter Chapter 3: --- Digital Filtering Method for Gray Scale Font --- p.19Filtering Process --- p.19Weighted Functions --- p.21Generation of Gray Scale Character --- p.23Results --- p.24More Experiments --- p.24Problems --- p.26Speed and Storage --- p.26Impression of Strokes --- p.27Thin strokes in the small-size character --- p.30New Approach to Generate Gray Scale Font --- p.30Chapter Chapter 4: --- Rasterization Algorithms --- p.32Outline Font --- p.32TrueType Font --- p.33Scan Conversion --- p.35Basic Outline-to-Bitmap Conversion --- p.35Scan-converting Polygon --- p.36Rasterization of a character --- p.36Intersecting Points and Ranges --- p.37Straight Lines --- p.37Quadratic Bezier Curves --- p.38Implementation Techniques --- p.39Approximation of quadratic Bezier curve by straight lines --- p.39Simplification of the Filling Process --- p.41The Rasterization Algorithm --- p.45Chapter Chapter 5: --- Direct Rasterization with Gray Scale --- p.46Rasterization with Gray Scale --- p.46Determination of Gray Value of Boundary-pixel --- p.50Preliminary Results --- p.54Hinting --- p.56Rasterization with Hinting --- p.56Strokes Migration --- p.57Hints Finding --- p.59Chapter Chapter 6: --- Results and Conclusion --- p.62Quality --- p.66Comparison with Black-and-White Character --- p.66Hinted Against Unhinted --- p.71Generation Speeds --- p.75Discussion and Comments --- p.78Practical Font System --- p.79Conclusion --- p.80Bibliography --- p.8

An Automated Algorithm for Approximation of Temporal Video Data Using Linear B'EZIER Fitting

This paper presents an efficient method for approximation of temporal video data using linear Bezier fitting. For a given sequence of frames, the proposed method estimates the intensity variations of each pixel in temporal dimension using linear Bezier fitting in Euclidean space. Fitting of each segment ensures upper bound of specified mean squared error. Break and fit criteria is employed to minimize the number of segments required to fit the data. The proposed method is well suitable for lossy compression of temporal video data and automates the fitting process of each pixel. Experimental results show that the proposed method yields good results both in terms of objective and subjective quality measurement parameters without causing any blocking artifacts.Comment: 14 Pages, IJMA 201

Rasterization techniques for Chinese outline fonts.

Kwong-ho Wu.Thesis (M.Phil.)--Chinese University of Hong Kong, 1994.Includes bibliographical references (leaves 72-75).Chapter 1 --- Introduction --- p.1Chapter 1.1 --- Outline Fonts --- p.2Chapter 1.1.1 --- Advantages and Disadvantages --- p.4Chapter 1.1.2 --- Representations --- p.4Chapter 1.1.3 --- Rasterization --- p.5Chapter 1.2 --- Introduction to This Thesis --- p.6Chapter 1.2.2 --- Organization --- p.7Chapter 1.2.1 --- Objectives --- p.7Chapter 2 --- Chinese Characters Fonts --- p.8Chapter 2.1 --- Large Character Set --- p.8Chapter 2.2 --- Font Styles --- p.8Chapter 2.3 --- Storage Problems --- p.9Chapter 2.4 --- Hierarchical Structure --- p.10Chapter 2.5 --- High Stroke Count --- p.11Chapter 3 --- Rasterization --- p.13Chapter 3.1 --- The Basic Rasterization --- p.13Chapter 3.1.1 --- Scan Conversion --- p.14Chapter 3.1.2 --- Filling Outline --- p.16Chapter 3.2 --- Font Rasterization --- p.17Chapter 3.2.1 --- Outline Scaling --- p.17Chapter 3.2.2 --- Hintings --- p.17Chapter 3.2.3 --- Basic Rasterization Approach for Chinese Fonts --- p.18Chapter 3.3 --- Hintings --- p.20Chapter 3.3.1 --- Phase Control --- p.20Chapter 3.3.2 --- Auto-Hints --- p.21Chapter 3.3.3 --- Storage of Hintings Information in TrueType Font and Postscript Font --- p.22Chapter 4 --- An Improved Chinese Font Rasterizer --- p.24Chapter 4.1 --- Floating Point Avoidance --- p.24Chapter 4.2 --- Filling --- p.25Chapter 4.2.1 --- Filling with Horizontal Scan Line --- p.25Chapter 4.2.2 --- Filling with Vertical Scan Line --- p.27Chapter 4.3 --- Hintings --- p.30Chapter 4.3.1 --- Assumptions --- p.30Chapter 4.3.2 --- Maintaining Regular Strokes Width --- p.30Chapter 4.3.3 --- Maintaining Regular Spacing Among Strokes --- p.34Chapter 4.3.4 --- Hintings of Single Stroke Contour --- p.42Chapter 4.3.5 --- Storing the Hinting Information in Font File --- p.49Chapter 4.4 --- A Rasterization Algorithm for Printing --- p.51Chapter 4.4.1 --- A Simple Algorithm for Generating Smooth Characters --- p.52Chapter 4.4.2 --- Algorithm --- p.54Chapter 4.4.3 --- Results --- p.54Chapter 5 --- Experiments --- p.56Chapter 5.1 --- Apparatus --- p.56Chapter 5.2 --- Experiments for Investigating Rasterization Speed --- p.56Chapter 5.2.1 --- Investigation into the Effects of Features of Chinese Fonts on Rasterization Time --- p.56Chapter 5.2.2 --- Improvement of Fast Rasterizer --- p.57Chapter 5.2.3 --- Details of Experiments --- p.57Chapter 5.3 --- Experiments for Rasterization Speed of Font File with Hints --- p.57Chapter 6 --- Results and Conclusions --- p.58Chapter 6.1 --- Observations --- p.58Chapter 6.1.1 --- Relationship Between Time for Rasterization and Stroke Count --- p.58Chapter 6.1.2 --- Effects of Style --- p.61Chapter 6.1.3 --- Investigation into the Observed Relationship --- p.62Chapter 6.2 --- Improvement of the Improved Rasterizer --- p.64Chapter 6.3 --- Gain and Cost of Inserting Hints into Font File --- p.68Chapter 6.3.1 --- Cost --- p.68Chapter 6.3.2 --- Gain --- p.68Chapter 6.4 --- Conclusions --- p.69Chapter 6.5 --- Future Work --- p.69Appendi

On the capture and representation of fonts

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The commercial need to capture, process and represent the shape and form of an outline has lead to the development of a number of spline routines. These use a mathematical curve format that approximates the contours of a given shape. The modelled outline lends itself to be used on, and for, a variety of purposes. These include graphic screens, laser printers and numerically controlled machines. The latter can be employed for cutting foil, metal. plastic and stone. One of the most widely used software design packages has been the lKARUS system. This, developed by URW of Hamburg (Gennany), employs a number of mathematical descriptions that facilitate the process of both modelling and representation of font characters. It uses a variety of curve formats, including Bezier cubics, general conics and parabolics. The work reported in this dissertation focuses on developing improved techniques, primarily. for the lKARUS system. This includes two algorithms which allow a Bezier cubic description, two for a general conic representation and, yet another, two for the parabolic case. In addition, a number of algorithms are presented which promote conversions between these mathematical forms; for example, Bezier cubics to a general conic form. Furthennore, algorithms are developed to assist the process of rasterising both cubic and quadratic arcs.This study was partly funded by the Science and Education Research Council (SERC)

A software automation framework for image-typeface matching in graphic design

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.Includes bibliographical references (pages 43-44).This research proposes the framework for an automation tool that facilitates the graphic design process of image-font pairing or matching. Considering traditional graphic design principles, a multi-step software algorithm was developed to emulate the process of determining proportions and visual axes of both images and fonts. The algorithm then matches these visual markers using a decision hierarchy to produce a ranking of appropriate fonts from an existing font dataset. To test the algorithm, 8 benchmark images were selected with varying proportions and visual axes. To build the font data set, each image was manually analyzed through a traditional graphic design process and then two fonts per image with similar, matching characteristics were manually selected. The 8 benchmark images and 16 fonts were then used as inputs into the proposed matching software program. The results of the manually prescribed font-image pairings and calculated matches were then compared. Two images had the intended font in the top 4, two images had one of the intended fonts in the top 4, and 4 images had neither of the intended fonts in the top 4. An additional step in image-font pairing includes detail matching by determining curvature similarities. This detail analysis will affect the pairing outcomes and should be further investigated. This research began to analyze these details, and makes recommendations for continuing this work. Additional future directions for this work include incorporating a user-interface to the matching algorithm, introducing expert testing, and down-selecting the first font pool based on deviation.by Taylor Javier Morris.S.M

Geometric distance fields of plane curves

This paper introduces a geometric generalization of signed distance fields for plane curves. We propose to store simplified geometric proxies to the curve at every sample. These proxies are constructed based on the differential geometric quantities of the represented curve and are used for queries such as closest point and distance calculations. We investigate the theoretical approximation order of these constructs and provide empirical comparisons between geometric and algebraic distance fields of higher order. We apply our results to font representation and rendering