In typography , a glyph ( Greek γλυφή glyphḗ , German 'engraved' ) is the graphic representation of a segmental , symbolic , iconic or indexical character in the form of a letter , part of a letter, a syllable , a logogram , a punctuation mark , special character , an Arabic numeral or a ligature , i.e. a specific graphic or typometric representation of a character or character within a writing system. The glyph forms a graphic unit.
Sign and glyph
The sign (Engl. Character ) is the abstract idea of a character, the glyph is the actual graphical representation. Electronic text like this one is stored as abstract characters and their appearance depends on the font you choose . In the simplest case, there is a single glyph for each visible character ( spaces are not visible characters) in a specific font (typeface and size). There are, however, notable deviations from this, and modern fonts can also contain several glyphs for one character.
However, several different letters or characters can also be represented by one and the same glyph. For example, in most fonts that include Latin, Greek and Cyrillic, the Latin capital A , the Cyrillic capital А and the Greek capital Α (alpha) cannot be distinguished from one another.
In data processing, the ambiguous English term character , roughly “abstract character”, includes spaces, control and formatting characters , in addition to normal characters, i.e. all characters necessary for text storage, processing and display, including those that are not assigned a glyph .
The character sequence fl can be represented by two individual glyphs for f and l or as a ligature by a single glyph.
The following characters are shown as single glyphs without a ligature:
The same characters are shown as ligatures. Each ligature is a glyph:
In special cases, individual glyphs can also be set overlapping to form the ligature glyph.
Glyphs and glyph variants
In many character systems, the shape of a character can be position-dependent. In this case, there are two or more glyphs for the character in question - regardless of the font. Examples:
- In the Arabic script there are several glyphs for a letter because the appearance of the letters is influenced by neighboring letters.
- In the Hebrew alphabet , five letters at the end of a word have a special shape. In these cases, two different glyphs are shown next to each other in the table of Hebrew letters (e.g. kaph and final kaph).
- The same applies to the Greek sigma , which is written at the end of the word with the glyph ς , but otherwise as σ .
- In Gothic script there are rules for the long (runde) and the round s.
Using different fonts also creates different glyphs for a single character, usually one glyph for each character in a particular font (see illustration at the top). However, for some characters (for example, point or hyphen), differences depending on the font - if they exist at all - cannot be determined or can only be determined when enlarged.
If there are very fine differences between different glyphs for the same character within a font, one also speaks of glyph variants . Johannes Gutenberg designed around 290 different characters to represent the characters of his alphabet for Bible printing.
Whether there are different glyphs (with clearly recognizable design differences) or different glyph variants (with less noticeable differences) within a font often depends on the subjective assessment of the viewer. Within a font family , there are usually different typefaces (variants of the font). Depending on the typeface, the characters appear wider or narrower and with different thicknesses (lean, normal, bold), often with more precise gradations (such as "semi-bold"). Depending on which font styles you are comparing, the differences between the glyphs of the same character can be noticeable or barely noticeable.
The graphic form (glyph) and the coding (character assignment to character position) also belong to the definition of characters in the computer. The same glyph can be used for several characters. For example, on old typewriters the umlaut characters ¨ were placed on a separate key and thus (for example on the type wheel ) formed a separate glyph. Together with the characters a, o and u they formed the characters ä, ö and ü. The same method can be used (internally) for character encoding in computer programs. The umlaut characters can also be displayed or combined on various keyboard layouts - such as the Spanish one.
When text is stored in the computer, there are also abstract characters that do not have glyphs assigned to them. The simplest examples of this are spaces or line breaks . Another example of a meaningful abstract character without a glyph is found in mathematical formulas. For example, “2a” is a form of representation of “2 × a”. In the short description you think of a multiplication sign . But if you want to evaluate an expression represented in the short version with a computer, an invisible (thus glyph-free) multiplication symbol is required semantically between “2” and “a”. It is included in Unicode as U + 2062 .
- ↑ Glyph in www.typolexikon.de
- ↑ uni-regensburg.de ( Memento of the original from September 11, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.