Biological Bar Codes in Human Faces
Facial features that allow us to recognize a familiar person or quickly distinguish human faces among other objects can be narrowed down to a certain sequence of parallel lines that look just like a notorious “bar code”. The discovery was made by Steven C. Dakin and his colleagues from Institute of Ophthalmology, London University College.
For a long time scientists have beleived that our ability to distinguish faces, a complex multistage process, is based upon a number of simple actions, like identifying key features or distances between key points (eyes, nose, mouth etc).
Face recognition software based on this theory has been developed quite successfully. Nevertheless, all the details of such comprehension still remain obscure. For this reason, various complementary or alternative theories appear (e.g. recognizing by nose).
Steven C. Dakin and his colleagues manipulated photographs of famous people to be recognized by the volunteers, in order to prove that facial identity information is conveyed largely via mechanisms tuned to horizontal visual structure formed by eyebrows, eyes and lips. Those visual structures can be simplified to interlacing dark and bright lines of variable width - same to those used in the “bar code”.
“Forehead and cheeks tend to glitter, whereas eyebrows and lips create shades. As a result, information-transmitting horizontal lines are formed within face structure” - explains Dakin.
“The “bar code” was designed as an effective way of transmitting machine information - the researchers say - since a sequence of straight lines is much more easily recognized (by a computer) than two-dimensional codes, such as digits. Apparently, human faces have evolved in the same direction in order to provide us with the ability to transmit information as reliable spatial sequence, needed for face detection and decoding”.
The researchers compared facial structures with images of other natural scenes, such as flowers or landscapes, and saw that only faces tend to show a distinctive sequence of horizontal lines. Such structure affords an advantage for the brain to detect faces easily against other objects.
The discovery may lead to further development of face detection and decoding software, which may prove useful for systems that identify suspects in the crowd. Besides, the discovery of a relatively simple code may explain our ability to “see” faces in the clouds or flames: there can be no faces there, instead, symmetrical dark and bright structures are formed, and human brain classifies them as faces.
Source: nauka21vek.ru
