Title :
Contrast sensitivity model of the human eye
Author :
Roka, Andras ; Galambos, Peter ; Baranyi, Peter
Author_Institution :
Comput. & Autom. Res. Inst., Hungarian Acad. of Sci., Budapest, Hungary
Abstract :
In this paper, we propose a mathematical model of human photopic contrast sensitivity. The model is based on a novel functional block diagram, focusing more on the information theoretical nature of human contrast sensitivity. At the same time, several other aspects of human vision are also considered. In order to obtain an estimate of the nonlinear projection of the retinal image, the numerical results of Drasdo and Fowler were used. Cone density measurements along the major meridians of the retina, performed by Curcio & Allen, were also used. Retinal midget ganglion cell receptive field density was extended to the far periphery, based on the results of Drasdo and colleagues and Curcio & Allen. Considering cell densities and optical properties of the human eye, the low-pass filtering components of human contrast sensitivity have been characterized by a simple but adequate mathematical formula. The high-pass filtering of neural origin was also estimated based on midget receptive field densities as well as other experimental results. Further models are presented for the calculation of photon noise, neural noise and spatial integration, according to the previous results in the literature. The model presented in this paper has been validated by several experimental measurements, both for foveal and peripheral vision, at several luminance levels and experimental set-ups. Results were shown to be better fitting than the model of Barten and Rovamo et al.
Keywords :
bio-optics; cellular biophysics; eye; neurophysiology; physiological models; vision; cell density; cone density measurement; contrast sensitivity model; eye optical properties; foveal vision; functional block diagram; high-pass filtering; human eye model; human photopic contrast sensitivity; low-pass filtering components; neural noise; nonlinear projection; peripheral vision; photon noise; retinal image; retinal midget ganglion cell receptive field density; spatial integration; Density measurement; Filtering; Humans; Low pass filters; Mathematical model; Nonlinear optics; Optical devices; Optical filters; Performance evaluation; Retina;
Conference_Titel :
Computational Intelligence and Intelligent Informatics, 2009. ISCIII '09. 4th International Symposium on
Conference_Location :
Luxor
Print_ISBN :
978-1-4244-5380-1
Electronic_ISBN :
978-1-4244-5382-5
DOI :
10.1109/ISCIII.2009.5342274