Smear (optics)

In optics, smear is used to refer to motion that has low temporal frequency relative to the integration/exposure time. This typically results from a relative rate of the image with respect to the detector (e.g., caused by movement in the scene). Smear is typically differentiated from jitter, which has a higher frequency relative to the integration time. Whereas smear refers to a relatively constant rate during the integration/exposure time, jitter refers to a relatively sinusoidal motion during the integration/exposure time.

The equation for the optical Modulation transfer function associated with smear is the standard sinc function associated with an extended sample

where u is the spatial frequency and is the amplitude of the smear in pixels.

References

Smear

Smear may refer to:

See also

Smear (Cristian Gheorghiu)

Cristian Gheorghiu became famous as an American street artist/graffiti artist and contemporary painter under the name of Smear in the 2000s. He further rose to prominence in a series of high-profile arrests and subsequent articles on the arrests and on his art which appeared in the Los Angeles Times from 2009 to 2011, followed by television appearances and further media coverage. In 2011 the Los Angeles Times called Smear "a subculture sensation" and his work has appeared in contemporary art galleries, and a solo museum exhibit in 2009. He was also a defendant in a civil lawsuit filed by the L.A. City attorney's office, a lawsuit which largely because of its First Amendment implications has garnered the attention of international media, including the Huffington Post, L.A. Weekly, the Los Angeles Times, and the Associated Press.

L.A. graffiti scene

Smear has been influential in the Los Angeles graffiti scene since the late 1990s. He was one of the first Los Angeles street artists to use street art methods in his graffiti. Before Smear, street art and graffiti art were considered separate communities. Graffiti practitioners at the time in the L.A. scene rarely ventured into the forms popularized by Smear. As a graffiti artist, Smear was further distinguished from the others by his uncomplicated graffiti writing style, unlike the intricate wildstyle works which are commonly a part of graffiti art. Smear's uncomplicated style used a spontaneous repertoire of images, designs and slogans. Among Smear's most famous street art images are his "Liquor Face" character (which momentarily appears in DreamWorks Pictures' animated film Bee Movie), and another image which is a shadowy depiction of Smear's own face, with "Smear" written underneath.

Smear (card game)

Smear (also known as Schmier) is a North-American trick-taking card game of the All Fours group, and a variant of Pitch (Setback). Several slightly different versions are played in the Upper Peninsula of Michigan, Minnesota, Northern and Central Iowa, Wisconsin and also in Ontario, Canada.

It is highly likely that the name is related to the German word schmieren, which is used in point-trick games such as Skat for the technique of discarding a high-value card on a trick which your partner is winning. The name might perhaps be connected to the fact that a high-scoring card may be discarded in a trick won by the player's partner, like in Pinochle, or even to "smudge," which is the highest bid in some forms of Pitch.

Ten-point partnership Smear

Partnership Smear is played by four players in fixed partnerships, sitting crosswise. It can also be played by six players in three partnerships. The following version is one of several described by John McLeod.

Deck and basic game structure

Optics

Optics is the branch of physics which involves the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviolet, and infrared light. Because light is an electromagnetic wave, other forms of electromagnetic radiation such as X-rays, microwaves, and radio waves exhibit similar properties.

Most optical phenomena can be accounted for using the classical electromagnetic description of light. Complete electromagnetic descriptions of light are, however, often difficult to apply in practice. Practical optics is usually done using simplified models. The most common of these, geometric optics, treats light as a collection of rays that travel in straight lines and bend when they pass through or reflect from surfaces. Physical optics is a more comprehensive model of light, which includes wave effects such as diffraction and interference that cannot be accounted for in geometric optics. Historically, the ray-based model of light was developed first, followed by the wave model of light. Progress in electromagnetic theory in the 19th century led to the discovery that light waves were in fact electromagnetic radiation.

Ptolemy

Claudius Ptolemy (/ˈtɒləmi/; Greek: Κλαύδιος Πτολεμαῖος, Klaúdios Ptolemaîos, [kláwdios ptolɛmɛ́ːos]; Latin: Claudius Ptolemaeus; c. AD 100 – c. 170) was a Greco-Egyptian writer, known as a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in the city of Alexandria in the Roman province of Egypt, wrote in Koine Greek, and held Roman citizenship. Beyond that, few reliable details of his life are known. His birthplace has been given as Ptolemais Hermiou in the Thebaid in an uncorroborated statement by the 14th-century astronomer Theodore Meliteniotes. This is a very late attestation, however, and there is no other reason to suppose that he ever lived anywhere else than Alexandria, where he died around AD 168.

Ptolemy was the author of several scientific treatises, three of which were of continuing importance to later Byzantine, Islamic and European science. The first is the astronomical treatise now known as the Almagest, although it was originally entitled the "Mathematical Treatise" (Μαθηματικὴ Σύνταξις, Mathēmatikē Syntaxis) and then known as the "Great Treatise" (Ἡ Μεγάλη Σύνταξις, Ē Megálē Syntaxis). The second is the Geography, which is a thorough discussion of the geographic knowledge of the Greco-Roman world. This manuscript was used by Christopher Columbus as the map for his westward-bound path to Asia, in which he discovered the hitherto unknown lands of the Americas. The third is the astrological treatise in which he attempted to adapt horoscopic astrology to the Aristotelian natural philosophy of his day. This is sometimes known as the Apotelesmatika (Ἀποτελεσματικά) but more commonly known as the Tetrabiblos from the Greek (Τετράβιβλος) meaning "Four Books" or by the Latin Quadripartitum.

Dioptrique

La dioptrique (in English Dioptrique, Optics, or Dioptrics), is a short treatise published in 1637 included in one of the Essays written with Discourse on the Method by Rene Descartes. In this essay Descartes uses various models to understand the properties of light. This essay is known as Descartes' greatest contribution to optics, as it is the first publication of the Law of Refraction.

First Discourse: On Light

The first discourse captures Descartes' theories on the nature of light. In the first model, he compares light to a stick that allows a blind person to discern his environment through touch. Descartes says:

Descartes' second model on light uses his theory of the elements to demonstrate the rectilinear transmission of light as well as the movement of light through solid objects. He uses a metaphor of wine flowing through a vat of grapes, then exiting through a hole at the bottom of the vat.

Second Discourse: On Refraction

Descartes uses a tennis ball to create a proof for the laws of reflection and refraction in his third model. This was important because he was using real-world objects (in this case, a tennis ball) to construct mathematical theory. Descartes' third model creates a mathematical equation for the Law of Refraction, characterized by the angle of incidence equalling the angle of refraction. In today's notation, the law of refraction states,