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Contrast resolution or contrast-detail is an approach to describing the image quality in terms of both the image contrast and resolution. Contrast resolution is usually measured by generating a pattern from a test object that depicts how image contrast changes as the structures being imaged get smaller and closer together.
Contrast sensitivity is typically expressed as the reciprocal of the threshold contrast for detection of a given pattern (i.e., 1 ÷ contrast threshold). [15] Using the results of a contrast sensitivity exam, a contrast sensitivity curve can be plotted, with spatial frequency on the horizontal, and contrast threshold on the vertical axis.
The "luminance contrast" is the ratio between the higher luminance, L H, and the lower luminance, L L, that define the feature to be detected.This ratio, often called contrast ratio, CR, (actually being a luminance ratio), is often used for high luminances and for specification of the contrast of electronic visual display devices.
Resolution depends on the distance between two distinguishable radiating points. The sections below describe the theoretical estimates of resolution, but the real values may differ. The results below are based on mathematical models of Airy discs, which assumes an adequate level of contrast. In low-contrast systems, the resolution may be much ...
A definition of resolution that is more in line with the perceived quality would instead use the spatial frequency at which the first zero occurs, 10 μm, or 100 LP/mm. Definitions of resolution, even for perfect imaging systems, vary widely. A more complete, unambiguous picture is provided by the optical transfer function.
Contrast, also known as gamma, is the slope of the tone reproduction curve in a log-log space. High contrast usually involves loss of dynamic range — loss of detail, or clipping, in highlights or shadows. Color accuracy is an important but ambiguous image quality factor. Many viewers prefer enhanced color saturation; the most accurate color ...
In contrast, expectorants lubricate your airway, which helps loosen up the mucus and make the secretions in your airway thinner. By loosening up the mucus, expectorants make your cough more ...
An LCD technology is dynamic contrast (DC), also called advanced contrast ratio (ACR), and smart contrast ratio (SCR [4]) and various other designations.When there is a need to display a dark image, a display that supports dynamic contrast underpowers the backlight lamp (or decreases the aperture of the projector's lens using an iris), but proportionately amplifies the transmission through the ...