1 May 2011 Imaging system fundamentals
Author Affiliations +
Abstract
Point-and-shoot, TV studio broadcast, and thermal infrared imaging cameras have significantly different applications. A parameter that applies to all imaging systems is Fλ/d, where F is the focal ratio, λ is the wavelength, and d is the detector size. Fλ/d uniquely defines the shape of the camera modulation transfer function. When Fλ/d<2, aliased signal corrupts the imagery. Mathematically, the worst case analysis assumes that the scene contains all spatial frequencies with equal amplitudes. This quantifies the potential for aliasing and is called the spurious response. Digital data cannot be seen; it resides in a computer. Cathode ray tubes, flat panel displays, and printers convert the data into an analog format and are called reconstruction filters. The human visual system is an additional reconstruction filter. Different displays and variable viewing distance affect the perceived image quality. Simulated imagery illustrates different Fλ/d ratios, displays, and sampling artifacts. Since the human visual system is primarily sensitive to intensity variations, aliasing (a spatial frequency phenomenon) is not considered bothersome in most situations.
©(2011) Society of Photo-Optical Instrumentation Engineers (SPIE)
Gerald C. Holst "Imaging system fundamentals," Optical Engineering 50(5), 052601 (1 May 2011). https://doi.org/10.1117/1.3570681
Published: 1 May 2011
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CITATIONS
Cited by 16 scholarly publications and 2 patents.
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KEYWORDS
Modulation transfer functions

Sensors

Image quality

Imaging systems

Cameras

Spatial frequencies

Optical transfer functions

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