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🔗 Computer science

Floyd–Steinberg dithering is an image dithering algorithm first published in 1976 by Robert W. Floyd and Louis Steinberg. It is commonly used by image manipulation software, for example when an image is converted into GIF format that is restricted to a maximum of 256 colors.

The algorithm achieves dithering using error diffusion, meaning it pushes (adds) the residual quantization error of a pixel onto its neighboring pixels, to be dealt with later. It spreads the debt out according to the distribution (shown as a map of the neighboring pixels):

${\displaystyle {\begin{bmatrix}&&*&{\frac {\displaystyle 7}{\displaystyle 16}}&\ldots \\\ldots &{\frac {\displaystyle 3}{\displaystyle 16}}&{\frac {\displaystyle 5}{\displaystyle 16}}&{\frac {\displaystyle 1}{\displaystyle 16}}&\ldots \\\end{bmatrix}}}$

The pixel indicated with a star (*) indicates the pixel currently being scanned, and the blank pixels are the previously-scanned pixels. The algorithm scans the image from left to right, top to bottom, quantizing pixel values one by one. Each time the quantization error is transferred to the neighboring pixels, while not affecting the pixels that already have been quantized. Hence, if a number of pixels have been rounded downwards, it becomes more likely that the next pixel is rounded upwards, such that on average, the quantization error is close to zero.

The diffusion coefficients have the property that if the original pixel values are exactly halfway in between the nearest available colors, the dithered result is a checkerboard pattern. For example, 50% grey data could be dithered as a black-and-white checkerboard pattern. For optimal dithering, the counting of quantization errors should be in sufficient accuracy to prevent rounding errors from affecting the result.

In some implementations, the horizontal direction of scan alternates between lines; this is called "serpentine scanning" or boustrophedon transform dithering.

In the following pseudocode we can see the algorithm described above. This works for any approximately linear encoding of pixel values, such as 8-bit integers, 16-bit integers or real numbers in the range [0,1].

for each y from top to bottom do
    for each x from left to right do
        oldpixel := pixel[x][y]
        newpixel := find_closest_palette_color(oldpixel)
        pixel[x][y] := newpixel
        quant_error := oldpixel - newpixel
        pixel[x + 1][y    ] := pixel[x + 1][y    ] + quant_error × 7 / 16
        pixel[x - 1][y + 1] := pixel[x - 1][y + 1] + quant_error × 3 / 16
        pixel[x    ][y + 1] := pixel[x    ][y + 1] + quant_error × 5 / 16
        pixel[x + 1][y + 1] := pixel[x + 1][y + 1] + quant_error × 1 / 16

When converting 16 bit greyscale to 8 bit, find_closest_palette_color() may perform just a simple rounding, for example:

find_closest_palette_color(oldpixel) = round(oldpixel / 256)

The pseudocode can result in pixel values exceeding the valid values (such as greater than 1 in a [0,1] representation). Such values should ideally be clipped by the find_closest_palette_color() function, rather than clipping the intermediate values, since a subsequent error may bring the value back into range. However, if fixed-width integers are used, wrapping of intermediate values would cause inversion of black and white, and so should be avoided.

🔗 United States 🔗 Terrorism 🔗 Socialism 🔗 Michigan 🔗 Chicago

The Weather Underground Organization (WUO), commonly known as the Weather Underground, was a radical left militant organization active in the late 1960s and 1970s, founded on the Ann Arbor campus of the University of Michigan. It was originally called the Weathermen. The WUO organized in 1969 as a faction of Students for a Democratic Society (SDS) largely composed of the national office leadership of SDS and their supporters. Beginning in 1974, the organization's express political goal was to create a revolutionary party to overthrow American imperialism.

The FBI described the WUO as a domestic terrorist group, with revolutionary positions characterized by black power and opposition to the Vietnam War. The WUO took part in domestic attacks such as the jailbreak of Timothy Leary in 1970. The "Days of Rage" was the WUO's first riot in October 1969 in Chicago, timed to coincide with the trial of the Chicago Seven. In 1970, the group issued a "Declaration of a State of War" against the United States government under the name "Weather Underground Organization".

In the 1970s, the WUO conducted a bombing campaign targeting government buildings and several banks. Some attacks were preceded by evacuation warnings, along with threats identifying the particular matter that the attack was intended to protest. Three members of the group were killed in an accidental Greenwich Village townhouse explosion, but none were killed in any of the bombings. The WUO communiqué issued in connection with the bombing of the United States Capitol on March 1, 1971 indicated that it was "in protest of the U.S. invasion of Laos". The WUO asserted that its May 19, 1972 bombing of the Pentagon was "in retaliation for the U.S. bombing raid in Hanoi". The WUO announced that its January 29, 1975 bombing of the United States Department of State building was "in response to the escalation in Vietnam".

The WUO began to disintegrate after the United States reached a peace accord in Vietnam in 1973, and it was defunct by 1977.

The group took its name from Bob Dylan's lyric, "You don't need a weatherman to know which way the wind blows", from the song "Subterranean Homesick Blues" (1965). That Dylan line was also the title of a position paper distributed at an SDS convention in Chicago on June 18, 1969. This founding document called for a "White fighting force" to be allied with the "Black Liberation Movement" and other radical movements to achieve "the destruction of U.S. imperialism and form a classless communist world".

🔗 Food and drink 🔗 Plants

Romanesco broccoli (also known as Roman cauliflower, Broccolo Romanesco, Romanesque cauliflower, or simply Romanesco) is an edible flower bud of the species Brassica oleracea. First documented in Italy in the 16th century, it is chartreuse in color, and has a form naturally approximating a fractal. When compared to a traditional cauliflower, it has a firmer texture and delicate, nutty flavor.

🔗 Color

Cosmic latte is the average color of the universe, found by a team of astronomers from Johns Hopkins University. In 2001, Karl Glazebrook and Ivan Baldry determined that the average color of the universe was a greenish white, but they soon corrected their analysis in a 2002 paper in which they reported that their survey of the light from over 200,000 galaxies averaged to a slightly beigeish white. The hex triplet value for cosmic latte is #FFF8E7.

The Dunning–Kruger effect is a cognitive bias in which people with low ability at a task overestimate their ability. It is related to the cognitive bias of illusory superiority and comes from people's inability to recognize their lack of ability. Without the self-awareness of metacognition, people cannot objectively evaluate their level of competence.

As described by social psychologists David Dunning and Justin Kruger, the bias results from an internal illusion in people of low ability and from an external misperception in people of high ability; that is, "the miscalibration of the incompetent stems from an error about the self, whereas the miscalibration of the highly competent stems from an error about others". Colloquially, people experiencing this bias are said to be "on Mount Stupid".

But in spite of the inherent appeal of Dunning and Kruger's claimed results, which align with many people's just world theories, their conclusions are strongly challenged when subjected to mathematical analysis and comparisons across cultures.

🔗 United States 🔗 Biography 🔗 Computing 🔗 Women scientists 🔗 Biography/science and academia 🔗 Women's History 🔗 Chicago 🔗 Catholicism 🔗 United States/Iowa

Mary Kenneth Keller, B.V.M. (December 17, 1913 – January 10, 1985) was an American Roman Catholic religious sister, educator and pioneer in computer science. She and Irving C. Tang were the first two people to earn a doctorate in computer science in the United States.

🔗 Board and table games

18XX is the generic term for a series of board games that, with a few exceptions, recreate the building of railroad corporations during the 19th century; individual games within the series use particular years in the 19th century as their title (usually the date of the start of railway development in the area of the world they cover), or "18" plus a two or more letter geographical designator (such as 18EU for a game set in the European Union). The games 2038, set in the future, and Poseidon and Ur, 1830 BC, both set in ancient history, are also regarded as 18XX titles as their game mechanics and titling nomenclature are similar despite variance from the common railroad/stock-market theme.

The 18XX series has its origins in the game 1829, first produced by Francis Tresham in the mid-1970s. 1829 was chosen as it was the year of the Rainhill Trials. 1830 was produced by Avalon Hill in 1986, and was the first game of the series widely available in the United States; it is seen as the basic 18XX game by the U.S. audience.

In addition to traditionally published games, the 18XX series has spawned self-published variants and games published by low-volume game companies.

With few exceptions (such as 2038), 18XX titles are multiplayer board games without random variables in their game mechanics.

🔗 Philosophy 🔗 Philosophy/Logic

Bulverism is a term for a rhetorical fallacy that combines circular reasoning with presumption or condescenscion. The method of Bulverism is to "assume that your opponent is wrong, and explain his error." The Bulverist assumes a speaker's argument is invalid or false and then explains why the speaker came to make that mistake, even if the opponents's claim is actually right, attacking the speaker or the speaker's motive. The term Bulverism was coined by C. S. Lewis to poke fun at a very serious error in thinking that, he alleges, recurs often in a variety of religious, political, and philosophical debates.

Similar to Antony Flew's "subject/motive shift", Bulverism is a fallacy of irrelevance. One accuses an argument of being wrong on the basis of the arguer's identity or motive, but these are strictly speaking irrelevant to the argument's validity or truth.

🔗 Internet culture

"i am lonely will anyone speak to me" is the title of a thread that was posted on the Internet forum of the video codec downloads site Moviecodec.com, and had become "the web's top hangout for lonely folk". The thread began July 14, 2004; it was the first hit when the phrase "I am lonely" was entered into the Google search engine though it has since dropped.

It was featured in the magazines Wired, Guardian Unlimited, and The New Yorker. Bjarne Lundgren, the webmaster of Moviecodec.com, has stated "Like-minded people tend to flock together and, in this case, Google helped in flocking them together on my site".

Mark Griffiths, a researcher in internet psychology at Nottingham Trent University in the UK, also addressed this question, stating: "There are a lot of lonely people out there. Some people rely heavily on technology and end up treating it as an electronic friend, a sounding board—just writing it down can make you feel better... That doesn't change their psychological world at that moment, but creating a kinship with like-minded people can help. You're all in this virtual space together."

Due to its large community, Bjarne created a new forum entitled "A Lonely Life", for the thread's numerous lonely inhabitants to move to. The original thread is now located on Moviecodec.com's branch site, The Lounge Forums.

As of December 24, 2016, the website the thread is hosted on was shut down and can no longer be accessed.

🔗 United States/U.S. Government 🔗 United States 🔗 Philately 🔗 Donald Trump 🔗 United States/U.S. presidential elections

The 2020 United States Postal Service crisis is a series of events that have caused backlogs and delays in the delivery of mail by the United States Postal Service (USPS). The crisis stems primarily from changes implemented by Postmaster General Louis DeJoy shortly after taking office in June 2020. The delays have had substantial legal, political, economic, and health repercussions.

There is controversy and speculation about whether the delays are unintended consequences of restructuring operations, or if they were intentionally created for political and/or financial gain. DeJoy has supported and donated to President Donald Trump, who has publicly linked his opposition to emergency funding for the Postal Service to his desire to restrict voting by mail in the 2020 elections.

On August 18, 2020, under heavy political and legal pressure, DeJoy announced that he would be "suspending" the policy changes until after the November 2020 election. He testified to the Senate on August 21, and to the House of Representatives on August 24, concerning the changes and their effects.