Arabic ligatures: Analysis and application in text recognition

The Arabic script allows the replacement of certain character sequences by more compact forms called ligatures. Such ligatures lack a systematic analysis despite their importance in Arabic text recognition research. In this paper, we present analysis of ligatures and compile a comprehensive list of Arabic ligatures. Then, we perform recognition experiments on a benchmark database to show the impact of ligatures annotation in Arabic databases. Finally, we propose several guidelines for the design of representative and compact Arabic databases from the aspect of ligatures.