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Em (typography)
An em (from ''Quad (typography), em quadrat'') is a Typographic unit, unit in the field of typography, equal to the currently specified Point (typography), point size. It corresponds to the Body height (typography), body height of the typeface. For example, one em in a 16-point typeface is 16 points. Therefore, this unit is the same for all typefaces at a given point size. The Whitespace character#Unicode, em space is one ''em'' wide. Typographic measurements using this unit are frequently expressed in decimal notation (e.g., 0.7 em) or as fractions of 100 or 1000 (e.g., em or em). The number of pixels per em varies depending on system. History In Sort (typesetting), metal type, the point size (and hence the ''em'', from ''em quad, em quadrat'') was equal to the line height of the metal body from which the letter rises. In metal type, the physical size of a letter could not normally exceed the em. A digital font's design space in digital type is called the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quad (typography)
In typography, a quad (originally ''wikt:quadrat#Etymology_2, quadrat'') was a metal spacer used in letterpress typesetting. The term was later adopted as the generic name for two common sizes of Space (punctuation), spaces in typography, regardless of the form of typesetting used. An em quad (originally ''m quadrat'') is a space that is one ''em (typography), em'' wide; as wide as the height of the font. An en quad (originally ''n quadrat'') is a space that is one ''en (typography), en'' wide: half the width of an em quad. Both are encoded as characters in the General Punctuation (Unicode block), General Punctuation code block of the Unicode character set as and , which are also defined to be canonically equivalent to and respectively. LaTeX markup uses \quad for an em quad, and has other related whitespace escape sequences. History In 1683, in Joseph Moxon's book on the art of printing, the terms ''m'' and ''n quadrat'' are attested: And as there is three Heighths or Sizes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrometre
The micrometre (English in the Commonwealth of Nations, Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a unit of length in the International System of Units (SI) equalling (SI standard prefix "micro-" = ); that is, one millionth of a metre (or one thousandth of a millimetre, , or about ). The nearest smaller common SI Unit, SI unit is the nanometre, equivalent to one thousandth of a micrometre, one millionth of a millimetre or one billionth of a metre (). The micrometre is a common unit of measurement for wavelengths of infrared radiation as well as sizes of biological cell (biology), cells and bacteria, and for grading wool by the diameter of the fibres. The width of a single human hair ranges from approximately 20 to . Examples Between 1 μm and 10 μm: * 1–10 μm – length of a typical bacterium * 3–8 μm – width of str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Measurement
Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events. In other words, measurement is a process of determining how large or small a physical quantity is as compared to a basic reference quantity of the same kind. The scope and application of measurement are dependent on the context and discipline. In natural sciences and engineering, measurements do not apply to nominal properties of objects or events, which is consistent with the guidelines of the International Vocabulary of Metrology (VIM) published by the International Bureau of Weights and Measures (BIPM). However, in other fields such as statistics as well as the social and behavioural sciences, measurements can have multiple levels, which would include nominal, ordinal, interval and ratio scales. Measurement is a cornerstone of trade, science, technology and quantitative research in many disciplines. Historically, many measurement syste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Centimetre
upright=1.35, Different lengths as in respect to the electromagnetic spectrum, measured by the metre and its derived scales. The microwave is in-between 1 meter to 1 millimeter. A centimetre (International spelling) or centimeter (American English), with SI symbol cm, is a Units of measurement, unit of length in the International System of Units (SI) equal to one hundredth of a metre, ''centi-'' being the SI prefix for a factor of . Equivalently, there are 100 centimetres in 1 metre. The centimetre was the base unit of length in the now deprecated centimetre–gram–second (CGS) system of units. Though for many physical quantities, SI prefixes for factors of 103—like ''milli-'' and ''kilo-''—are often preferred by technicians, the centimetre remains a practical unit of length for many everyday measurements; for instance, human height is commonly measured in centimetres. A centimetre is approximately the width of the fingernail of an average adult person. Equivalenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pixel
In digital imaging, a pixel (abbreviated px), pel, or picture element is the smallest addressable element in a Raster graphics, raster image, or the smallest addressable element in a dot matrix display device. In most digital display devices, pixels are the smallest element that can be manipulated through software. Each pixel is a Sampling (signal processing), sample of an original image; more samples typically provide more accurate representations of the original. The Intensity (physics), intensity of each pixel is variable. In color imaging systems, a color is typically represented by three or four component intensities such as RGB color model, red, green, and blue, or CMYK color model, cyan, magenta, yellow, and black. In some contexts (such as descriptions of camera sensors), ''pixel'' refers to a single scalar element of a multi-component representation (called a ''photosite'' in the camera sensor context, although ''wikt:sensel, sensel'' is sometimes used), while in yet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pica (typography)
The pica is a typographic unit of measure corresponding to approximately of an inch. One pica is further divided into 12 Point (typography), points. In printing, three pica measures are used: * The French pica of 12 Didot points (also called Cicero (typography), cicero) generally is: 12 × 0.376 = . * The American pica of . It was established by the United States Type Founders' Association in 1886. In TeX one pica is of an inch. * The contemporary computer PostScript pica is exactly of an inch, i.e. 0.1 in or 4.2 mm. Publishing applications such as Adobe InDesign and QuarkXPress represent pica measurements with whole-number picas left of a lower-case ''p'', followed by the points number, for example: 5p6 represents 5 picas and 6 points, or 5 picas. Cascading Style Sheets (CSS) defined by the World Wide Web Consortium use pc as the abbreviation for pica ( of an inch), and pt for point ( of an inch). The pica is also used in measuring the font capacity and is applied in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whitespace Characters
A whitespace character is a character (computing), character data element that represents White space (visual arts), white space when text string, text is Rendering (computer graphics), rendered for display by a computer. For example, a ''Space (punctuation), space'' character (, ASCII 32) represents blank space such as a word divider in a Western writing system, script. A printable character results in output when rendered, but a whitespace character does not. Instead, whitespace characters define the layout of text to a limited degree, interrupting the normal sequence of rendering characters next to each other. The output of subsequent characters is typically shifted to the right (or to the left for right-to-left script) or to the start of the next line. The effect of multiple sequential whitespace characters is cumulative such that the next printable character is rendered at a location based on the accumulated effect of preceding whitespace characters. The origin of the te ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Responsive Web Design
Responsive web design (RWD) or responsive design is an approach to web design that aims to make web pages render well on a variety of devices and window or screen sizes from minimum to maximum display size to ensure usability and satisfaction. A responsive design adapts the web-page layout to the viewing environment by using techniques such as fluid proportion-based grids, flexible images, and CSS3 media queries, an extension of the @media rule, in the following ways: * The fluid grid concept calls for page element sizing to be in relative units like percentages, rather than absolute units like pixels or points. * Flexible images are also sized in relative units, so as to prevent them from displaying outside their containing element. * Media queries allow the page to use different CSS style rules based on characteristics of the device the site is being displayed on, e.g. width of the rendering surface (browser window width or physical display size). *Responsive layouts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-breaking Space
In word processing and digital typesetting, a non-breaking space (), also called NBSP, required space, hard space, or fixed space (in most typefaces, it is not of fixed width), is a space character that prevents an automatic line break at its position. In some formats, including HTML, it also prevents consecutive whitespace characters from collapsing into a single space. Non-breaking space characters with other widths also exist. Uses Despite having layout and uses similar to those of whitespace, it differs in contextual behavior. Non-breaking behavior Text-processing software typically assumes that an automatic line break may be inserted anywhere a space character occurs; a non-breaking space prevents this from happening (provided the software recognizes the character). For example, if the text "100 km" will not quite fit at the end of a line, the software ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of XML And HTML Character Entity References
In SGML, HTML and XML documents, the logical constructs known as ''character data'' and ''attribute values'' consist of sequences of characters, in which each character can manifest directly (representing itself), or can be represented by a series of characters called a ''character reference'', of which there are two types: a ''numeric character reference'' and a ''character entity reference''. This article lists the character entity references that are valid in HTML and XML documents. A character entity reference refers to the content of a named entity. An entity declaration is created in XML, SGML and HTML documents (before HTML5) by using the syntax in a document type definition (DTD). Character reference overview In HTML and XML, a ''numeric character reference'' refers to a character by its Universal Coded Character Set/Unicode ''code point'', and uses the format: &#x''hhhh''; or &#''nnnn''; where the x must be lowercase in XML documents, ''hhhh'' is the code po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fullwidth Forms
In CJK (Chinese, Japanese, and Korean) computing, graphic characters are traditionally classed into fullwidth and halfwidth characters. Unlike monospaced fonts, a halfwidth character occupies half the width of a fullwidth character, hence the name. ''Halfwidth and Fullwidth Forms'' is also the name of a Unicode block U+FF00–FFEF, provided so that older encodings containing both halfwidth and fullwidth characters can have lossless translation to and from Unicode. Rationale In the days of text mode computing, Western characters were normally laid out in a grid on the screen, often 80 columns by 24 or 25 lines. Each character was displayed as a small dot matrix, often about 8 pixels wide, and an SBCS (single-byte character set) was generally used to encode characters of Western languages. For aesthetic reasons and readability, it is preferable for Chinese characters to be approximately square-shaped, therefore twice as wide as these fixed-width SBCS characters. As these w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
