title: Natural images from the birthplace of the human eye.
abstract: Here we introduce a database of calibrated natural images publicly available through an easy-to-use web interface. Using a Nikon D70 digital SLR camera, we acquired about six-megapixel images of Okavango Delta of Botswana, a tropical savanna habitat similar to where the human eye is thought to have evolved. Some sequences of images were captured unsystematically while following a baboon troop, while others were designed to vary a single parameter such as aperture, object distance, time of day or position on the horizon. Images are available in the raw RGB format and in grayscale. Images are also available in units relevant to the physiology of human cone photoreceptors, where pixel values represent the expected number of photoisomerizations per second for cones sensitive to long (L), medium (M) and short (S) wavelengths. This database is distributed under a Creative Commons Attribution-Noncommercial Unported license to facilitate research in computer vision, psychophysics of perception, and visual neuroscience.
authors.affiliation: Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America. gtkacik@ist.ac.at
authors.forename: Gašper
authors.initials: G
authors.lastname: Tkačik
authors.forename: Patrick
authors.initials: P
authors.lastname: Garrigan
authors.forename: Charles
authors.initials: C
authors.lastname: Ratliff
authors.forename: Grega
authors.initials: G
authors.lastname: Milčinski
authors.forename: Jennifer M
authors.initials: JM
authors.lastname: Klein
authors.forename: Lucia H
authors.initials: LH
authors.lastname: Seyfarth
authors.forename: Peter
authors.initials: P
authors.lastname: Sterling
authors.forename: David H
authors.initials: DH
authors.lastname: Brainard
authors.forename: Vijay
authors.initials: V
authors.lastname: Balasubramanian
mesh_terms: D000818:Animals; D002138:Calibration; D005123:Eye; D006801:Humans; D020407:Internet; D014584:User-Computer Interface