ABSTRACT
This chapter investigates how to recover textural patterns such as figures and words from eroded outdoor rock surfaces. Some case studies including representative archeological sites worldwide, from prehistoric to modern eras, will be reported. Rock art is perhaps the oldest cultural heritage on earth. For more than ten thousand years, their ancestors have carved figures on smooth rock surfaces by pecking and scratching, generating textural patterns under the sun. Unfortunately most outdoor rock art surfaces have weathered and are disappearing. They have been cracked, colored, eroded, or accumulated lichen or moss, and dirt. Recovering the illegible art on the damaged surfaces has been a challenging task. Laser and pattern projection scanners are the most accurate three dimensional digitizing devices. Polynomial Texture Map is an effective imaging and reconstruction tool without depth map. The meaningful discoveries cannot happen without an intimate understanding of the background knowledge, such as the linguistics, typology, and crafting.
