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In geometric optics, distortion is a deviation from rectilinear projection; a projection in which straight lines in a scene remain straight in an image.It is a form of optical aberration that may be distinguished from other aberrations such as spherical aberration, coma, chromatic aberration, field curvature, and astigmatism in a sense that these impact the image sharpness without changing an ...
The log-spectral distance (LSD), also referred to as log-spectral distortion or root mean square log-spectral distance, is a distance measure between two spectra. [1] The log-spectral distance between spectra () and ^ is defined as p-norm:
CMB spectral distortions are tiny departures of the average cosmic microwave background (CMB) frequency spectrum from the predictions given by a perfect black body.They can be produced by a number of standard and non-standard processes occurring at the early stages of cosmic history, and therefore allow us to probe the standard picture of cosmology.
The reverse, in which the perimeter is magnified more than the center, is known as "pincushion distortion" (figure 3b). This effect is called lens distortion or image distortion, and there are algorithms to correct it. Systems free of distortion are called orthoscopic (orthos, right, skopein to look) or rectilinear (straight lines). Figure 4
Fiveable, an online learning community for high school students, made its first-ever acquisition earlier this week: Hours, a virtual study platform built by a 16-year-old. Fiveable is a free ...
A closely related effect is the Kaiser effect, in which the distortion is caused by the coherent motions of galaxies as they fall inwards towards the cluster center as the cluster assembles. [2] Depending on the particular dynamics of the situation, the Kaiser effect usually leads not to an elongation, but an apparent flattening ("pancakes of ...
with the distortion parameter [,]. This yields the f-tan theta condition (1) in the special case k = 1 {\displaystyle k=1} . The case k = 0.5 {\displaystyle k=0.5} is known as the circle condition and provides the pincushion-distorted pattern which was implemented by Helmholtz in his checkerboard. [ 7 ]
In astronomy, seeing is the degradation of the image of an astronomical object due to turbulence in the atmosphere of Earth that may become visible as blurring, twinkling or variable distortion. The origin of this effect is rapidly changing variations of the optical refractive index along the light path from the object to the detector.