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Colorimetry
Published in John G. Webster, Halit Eren, Measurement, Instrumentation, and Sensors Handbook, 2017
Color vision and perception is complex and has been extensively studied. Ninety-two percent of men and 99.5% of women have “normal” color vision. The eye’s lens focuses images on the light-sensitive retina. Rod cells make up the majority of the retina and are sensitive to low levels of illumination (night vision). Cone cells provide color vision and are located in a small area of the retina called the foveal pit. There are three types of cone cells. One type of cone cells has peak sensitivity to blue light, one type to green light, and one type to red light. Signals from the cone cells are transmitted to the brain where they are processed into color perceptions.
Molecular Electronics: Device-Level and System-Level Considerations
Published in Sergey Edward Lyshevski, Molecular Electronics, Circuits, and Processing Platforms, 2018
The human retina has ~125 million rod cells and ~6 million cone cells. An enormous amount of data, among other tasks, is processed by the visual system and brain in real time. Real-time 3D image processing, ordinarily accomplished even by primitive vertebrates and insects that consume less than 1 μW cannot be performed by envisioned processors with trillions of transistors, device switching speed of 1 THz, circuit speed of 10 GHz, device switching energy of 1 × 10−16 J, writing energy of 1 × 10−16 J/bit, read time of 10 nsec, and so forth.
Optical fiber communication and sensitivity
Published in Muhammad Arif, Guojun Wang, Mazin Abed Mohammed, Md Tabrez Nafis, Vehicular Ad Hoc Networks, 2023
Salma Masuda Binta, Mohammed Hossam-E Haider, Mohammad Farhan Ferdous
In visual neuroscience, spectral sensitivity is used to describe the different characteristics of the photopigments in the rod cells and cone cells in the retina of the eye. It is known that the rod cells are more suited to scotopic vision and cone cells to photopic vision and that they differ in their sensitivity to different wavelengths of light. It has been established that the maximum spectral sensitivity of the human eye under daylight conditions is at a wavelength of 555 nm, while at night the peak shifts to 507 nm.
Calculation of Mesopic Luminance Using per Pixel S/P Ratios Measured with Digital Imaging
Published in LEUKOS, 2019
Mikko Maksimainen, Matti Kurkela, Pramod Bhusal, Hannu Hyyppä
The human retina consists of cone cells used for accurate day and color vision and rod cells applied for dark vision. Day vision is also called “photopic vision,” and dark vision is called “scotopic vision.” The sensitivity peaks for photopic and scotopic visions are 555 nm and 507 nm, respectively (CIE 1990; Crawford 1949). Thus, scotopic vision is more sensitive to shorter wavelength (bluish) light, and photopic vision is more sensitive to longer wavelength (reddish) light. However, in the luminance range of 0.005–5.0 cd/m2, partly scotopic and partly photopic vision applies (CIE 2010). This region is known as the “mesopic region,” and the vision for this region is mesopic vision. In the CIE 191 system for mesopic photometry, the mesopic sensitivity curve is calculated as follows: