## 1 Introduction  
### Cuneiform Tablets Documentation  
Clay tablets are a writing medium that first appeared in Mesopotamia in the last centuries of the fourth millennium BCE. Although clay might seem to be an inconvenient material for writing, clay tablets remained in use for more than three thousand years and were adopted by state chanceries, administrative structures, and private people in a wide geographical area that includes Mesopotamia, Iran, Syria, the Levant, Turkey, Greece, and Egypt. In Western Asia and in Egypt, cuneiform characters were impressed in clay by means of a stylus. The dimension, format, and layout of cuneiform tablets varied according to scribal conventions, time, place, and the purpose of the written text. Cuneiform tablets were produced in both rectangular and square formats; they range in size from as little as 3 cm \(\times\) 3 cm to as large as 40 cm \(\times\) 25 cm. All tablets have a convex form, and some of them are shaped like pillows. After forming a tablet from damp clay and smoothing the surface, scribes could write on one or both sides of the tablet as well as on the edges. When the writing process was completed, clay tablets were either dried in the sun or baked [1]. The scientific publication of cuneiform tablets has evolved over time, in step with the available technology. In the nineteenth century, cuneiform tablets were published in the form of hand-drawn copies. Epigraphists copied the tablets either at the sites where they were found or in the museums where they were preserved. Although these hand copies were made by experts, they incorporated a high degree of subjectivity depending on what the individual copyist saw on the tablet--especially when the surface of the tablet was damaged and the intricate cuneiform signs were only partially preserved, as was often the case. Scholars had to interpret the traces visible on the tablet, and sometimes they overinterpreted what they saw. The development of photography offered the possibility of a more objective representation of the written surfaces of clay tablets. Although photography had been invented in the 1820s, it was not commonly used for commercial and artistic purposes until the second half of the nineteenth century. We are indebted to the photographer [PERSON] (1819-1869) for the first photographs of cuneiform tablets. [PERSON] founded the Photographic Society, later called the Royal Photographic Society, in 1853. In the following year, he was appointed as the first official photographer of the British Museum in London and immediately started taking pictures of the tablets in the rich collection [2]. Until recently, hand copies and analogue (film-based) photographs remained the only available visual media for recording and studying cuneiform tablets. Today, with the aid of computers and digital photography, several scientific institutions have created data sets of cuneiform tablets. For example, the Cuneiform Digital Library Initiative (CDLI), founded by [PERSON] at University of California, Los Angeles (UCLA), aims to preserve digital images of cuneiform documents in public museums and private collections available on the internet. About 350,000 cuneiform tablets are currently accessible on the CDLI web site [3]. This rich collection of tablets in the form of digital images and data is a very useful tool for researchers. A major drawback of two-dimensional analogue photography is the difficulty of accurately recording cuneiform signs on the surface of curved tablets, which can be inscribed on all six sides. Digital photography and photogrammetry capture 3D images of tablets, eliminating human error on the part of copyists and allowing accurate paleographic studies. The CDLI team, in collaboration with the Max Plank Institute, has begun scanning cuneiform tablets with a smart scanner produced by Breuckmann [3; 4]. Museums around the world are tackling the digitalization of cuneiform tablets using different techniques and instruments [5; 6; 7].