Signature identification and verification are some of the biometric systems used for personal identification. Signatures can be considered as authentication of an individual by the analysis of handwriting style, subjected to inter-personal and intra-personal variations. This paper presents an extensive systematic overview of online and offline signature identification and verification techniques. In offline signature verification, surveys related to two approaches, namely, writer-dependent, and writer-independent approaches are presented. Moreover, the compiled study of feature extraction and classification techniques used for signature identification and verification process has also been incorporated. Several databases introduced in the literature are considered to evaluate different signature identification and verification techniques and corresponding results are reported in this article. The entire survey is further summarized in the form of a table for comparisons. In order to reveal the superiority of the present survey, the comparison of the present survey with the existing recent survey works has also been presented. Finally, future directions are provided for further research.

签名识别和验证是用于个人身份识别的一些生物识别系统。通过对笔迹风格的分析，签名可以被认为是对个人的认证，受到人与人之间的差异。本文对在线和离线签名识别和验证技术进行了广泛的系统概述。在离线签名验证中，提出了与两种方法相关的调查，即依赖于作者的方法和独立于作者的方法。此外，还包括对用于签名识别和验证过程的特征提取和分类技术的综合研究。考虑了文献中介绍的几个数据库来评估不同的签名识别和验证技术，并在本文中报告了相应的结果。整个调查进一步以表格的形式进行总结，以供比较。为了揭示本次调查的优越性，还对本次调查与已有的近期调查工作进行了比较。最后，为进一步的研究提供了未来的方向。