International Journal of Electrical & Computer Sciences IJECS-IJENS Vol:9 No:10 5 93210-6565 IJECS-IJENS © December 2009 IJENS I J E N S Abstract — For many years, tools authoring for e-documents composition has been tailored for the English script’s needs. The localization of these tools to Arabic alphabet based writings is not an easy task, because of the great typographical and structural characteristic differences, and also because Arabic typography needs to process the text and analyze it contextually so that it can be typed according to the strict rules of Arabic calligraphy. Most typesetting tools seek to composite Arabic documents through adaptation of fonts capability to Latin based systems or by adaptation of the tools themselves to Arabic writing rules, and this is not an easy job due to the necessity of complex contextual analysis of Arabic writing and processing algorithms which differ from those in Latin based systems. The main purpose of this survey is to explore Arabic typography rules and to review the current Arabic typesetting systems. Such systems have been adapted to process special Arabic documents such as Scientific, Qur’anic and Multilingual documents. Research trends to date are summarized, and challenges confronting the development of high quality Arabic typography are identified. These challenges include the need for better algorithms for justification of Arabic text without relying on the Kashida, diacritical mark positioning and composition of dynamic fonts. Index Term— Arabic, Encoding, Font, Typesetting. I. INT RODUCT ION The Arabic language is native to roughly three hundred million people. The Arabic script is one of the most used in the world, not only by Arabs but also by the Islamic world as it is the script used to write the Qur‟an, the holy book of Muslims. Moreover, the Arabic script is used, in various slightly extended versions, to write many major languages. It is constituted in its basic form by 28 letters including 3 long vowels. Additionally there are short vowels, a total combination of 13. The process of typesetting languages using the Arabic script is more challenging and more complex than typesetting using the Latin script because of the requirement for special needs and strict rules. The contextual rules of the Arabic script are independent of the language, font and style and have no exception. In terms of Arabic e-document composition, the current tools still lack the ability to accommodate all of the Arabic script characteristics. Arabic script will benefit from the development of smart fonts to deal with complex script. II. ARABIC WRITING CHARACTERISTICS In terms of Arabic type design, the typographer must take into account a number of characteristics and rules of Arabic script. A good awareness of these characteristics leads to professional design of Arabic type. A. Direction of writing Arabic is a unidirectional script in which the writing spreads out from right-to-left. Nowadays, Arabic mathematical documents adopt Latin alphabetic symbols which has led some to believe that Arabic writing is bidirectional because of the current mixing of Arabic strings with Latin based expressions [8]. B. Cursivity The Latin based writing is based on the use of independent characters. In Arabic, only the cursive style is allowed. This cursivity implies four different forms for the same letter according to its position in the word: initial, middle, final and isolated: [2][8]. C. Ligatures Arabic script is extremely rich in ligatures due to the cursive nature of writing. Some ligatures are mandatory while others are optional and exist only for aesthetic reasons, legibility or justification [2]. As shown in the following examples, the ligature can appear in various degrees: D. Diacritic dot Diacritic dots are a measurement unit marked by the feather of the used calligraphy pen [5][8]. The semantic role of diacritic dots is that certain letters are characterized by the presence, number and positions of these dots [5]. For example, the basic glyph gives several letters according to the number of diacritic dots which appear above or below: and It is also used by calligraphers as a measurement unit to regularize the dimensions and the metrics of glyphs (Figure 1) [5][8]. Arabic Typography: A Survey Aqil Azmi and Abeer Alsaiari Fig. 1. Arabic letter Alef metrics