Departmental Colloquium by Olivier Morin
(Institut Jean Nicod, ENS, PSL, Paris & Max Planck Institute for the Science of Human History, Jena)
Information in images
How do images carry information? This question, usually addressed by semioticians or philosophers, can be answered quantitatively. This talk will present a framework that uses information theory to study and predict how the amount of information that images can carry may evolve. This framework focuses on graphic codes—images conventionally associated with meanings, as found in writing systems, pictographs, coin designs, heraldry, digital communication, etc. It considers three forms of information that a visual symbol may carry: complexity, distinctiveness, and specificity. A symbol's complexity assesses the cognitive costs carried by the act of processing and storing it. Its distinctiveness measures to what degree it stands out relative to other symbols. Its specificity quantifies the degree of precision that it is capable of when pointing at objects outside itself. All three types of information can be tracked using measures derived from information theory. These allow us to bring an evolutionary and quantitative perspective to classical semiotic questions. This framework will be illustrated with a range of naturalistic studies, considering cultural history in a quantitative light.