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Electronic speckle pattern interferometry (ESPI), [1] also known as TV holography, is a technique that uses laser light, together with video detection, recording and processing, to visualise static and dynamic displacements of components with optically rough surfaces. The visualisation is in the form of fringes on the image, where each fringe ...
The pattern is the same regardless of how it is imaged, just as if it were a painted pattern. The "size" of the speckles is a function of the wavelength of the light, the size of the laser beam which illuminates the first surface, and the distance between this surface and the surface where the speckle pattern is formed.
[3] [4] The shift-and-add method (more recently "image-stacking" method) is a form of speckle imaging commonly used for obtaining high quality images from a number of short exposures with varying image shifts. [5] [6] It has been used in astronomy for several decades, and is the basis for the image stabilisation feature on some cameras. The ...
The speckle pattern is a mixture of interference patterns and natural acoustic reflections. [1] These reflections are also described as speckles or markers. The pattern being random, each region of the myocardium has a unique speckle pattern (also called patterns, features, or fingerprints) that allows the region to be tracked. The speckle ...
Each star should appear as a single Airy pattern, but the atmosphere causes the images of the two stars to break up into two patterns of speckles (one pattern above left, the other below right). The speckles are a little difficult to make out in this image due to the coarse pixel size on the camera used (see the simulated images below for a ...
Michel-Lévy interference colour chart issued by Zeiss Microscopy. In optical mineralogy, an interference colour chart, also known as the Michel-Levy chart, is a tool first developed by Auguste Michel-Lévy to identify minerals in thin section using a petrographic microscope.
Twinkl was founded by husband and wife Jonathan and Susie Seaton. [2] [3] Susie, a primary school teacher, had noticed there was a lack of ready-made, high-quality educational materials and classroom content available to teachers.
Once the images are acquired, processing can begin. A flat-field consists of two numbers for each pixel, the pixel's gain and its dark current (or dark frame). The pixel's gain is how the amount of signal given by the detector varies as a function of the amount of light (or equivalent).