Glossary

Antialiasing:: Antialiasing describes the smoothing of the edges of fonts. Therefore pixels are added at the edges. The hue of the added pixels is between the colour of the font and the background colour
bitmap fonts:: Those fonts which have characters, specified as patterns of tiny dots. These patterns are necessary for every character in the font in all normal sizes. This method has a definite shortfall. If a pattern is not created for a certain size of a bitmapped character, a pattern for another size is contorted to provide the requested size. If you do this, dots in the original pattern are simply made larger. The net results are characters that display the ‘stair-case effect’. Each Glyph is stored like a screened picture and is dependent on the resolution of the output medium. Microsoft used *.fnt and *.fon as format for their bitmap fonts, Adobe uses the *bdf and *.abf format to save the fonts. Bitmaps take up much less memory, which is especially important for devices sold in areas of the world where the characters are so much more complex than Western fonts. And perhaps most importantly, all of these devices require small font sizes, and scalable fonts do not look good at small sizes. Here are some advantages bitmap fonts have nowadays: If text must fit within a window, bitmap fonts can guarantee that every character is the exact pixel width wide. They are used in text passages that need high quality output and do not need to be editable. Bitmap fonts exactly define the distance between characters and control the spacing between lines of text, tracking and kerning are not applicable. Bitmap fonts at the same point size as scalable fonts are larger and easier to read. Bitmap fonts contain the exact character set we need, whether for Windows, DOS, or special symbols.
brightness:: This attribute is responsible for the intensity of the visual attraction of the colour-hue. The range varies from light white, to dark black colour perception, which we can recognise via the cones in our eyes.
CIE:: Commission International de l'Eclairage
CIE_LUV:: Colour system based on the velencimetric measurements of colours (Böhringer et al. 2003).
CMYK:: Cyan Magenta Yellow Black, the base colours of the subtractive colour model.
colour appearance:: For someone with normal colour vision, the colour of an object will depend upon three things: - the wavelength of the light falling on the object, - the reflection properties of the object, and - the context in which it is seen. Two objects with different reflection properties can appear to be matched in colour under one light source (a metameric match’) but look quite different from each other under a different source. Individual wavelengths give rise to the sensation of a particular colour, as can be seen in the colours of the rainbow. White’ daylight, containing all wavelengths, is split into its individual wavelengths because the refractive index of water is wavelength-dependent. Consequently, the position of the colour within the rainbow is a function of the wavelength that gives rise to that sensation, with the short-wavelength radiation (seen as purple-blue) at one end, the long-wavelength radiation (seen as red) at the other, and the middle wavelengths (seen as green, yellow and orange) between them.
cones:: Human beings have 3 kinds of cones. One for perceiving Red, another one for Green and one for Blue. Their differences are continuously analysed and sent to our brain. Deeper information can be found on the following web-page: http://www.yorku.ca/eye/specsens.htm
Displaying on a Colour Monitor:: Via 3 electron beams and 3 kinds of phosphorus, 3 dots are activated to gleam in red, green and blue. Such dots, we call ‘picture elements’ or short: pixels. One such triplet forms 1 gleaming point we can perceive. The applied RGB system gives you the possibility to depict all colours possible for the RGB colour space depending on the intensity of the beam reaching the gleaming layer. The resolution of the screen depends on the interval between two triplet points. Depending on the quality of the graphic card, different colour depths are possible.
DPI:: Dots per Inch
DTP:: ‘Desktop Publishing’ is the process of using the computer and certain types of software to combine text graphics in order to produce documents such as newsletters, brochures, books, maps, etc.- basically any kind of document that produces visual communication. It is necessary to differentiate between drawing, painting and page layout programs. It allows a professional organisation of your documents that enables a successful printing process (Adobe).
Exonym:: These are names of places written in a language that is not spoken in the area where you are, but just outside this area. An example is: Genf is the German version for the original Genève. It is still often used in school atlases and can’t be eliminated completely and also shouldn’t be eliminated because of its historic rootage and preserving of the homeland dialect.
generalisation:: Selection and simplified representation of detail appropriate to the scale and/or the purpose of a map (ICA 1973).
hue:: This attribute is responsible for the perception of the tone itself. It sets colour groups like green red or orange.
kerning:: The adjustment of horizontal space between individual characters in a line of text. Adjustments in kerning are especially important in large displays and headline text lines. Without kerning adjustments, many letter combinations can look awkward. The objective of kerning is to create visually equal spaces between all letters so that the eye can move smoothly along the text.
lightness:: This attribute is responsible for the intensity of the visual attraction of the colour-hue. The range varies from light white, to dark black colour perception, that we can recognise via the cones in our eyes.
line spacing:: The space between to lines of type. It can be a fixed number of points or relative to the font size.
perceptive oriented colour models:: These models work with values of hue, saturation and brightness or sometimes also called lightness. They are adapted to man's perception. We place the HSB or HSL and the LCH model into this category.
physical - technical models:: These models describe colours as mixture of 3 primary colours. Their differences lay mostly in the chosen primary colours and the chosen type of mixing system. The RGB, CMYK and CIE LAB as well as the CIE LUV model belong in this section.
PostScript:: Developed by Apple Systems Inc. in 1985, PostScript is a page description language, which allows the appearance of a printed page to be described in a device-independent manner. It also runs on all major operating platforms. You can identify PostScript files by its suffix ‘ps’. Printing then becomes a two-stage process: An application language produces a description of the text, graphical shapes and image appearance on printed pages not as pixels but as mathematical shapes and curves. PostScript is used by certain printers with built-in PostScript interpreters and by graphics programs that create PostScript files. An advantage of PostScript is that it is resolution-independent and can consequently support the highest resolution of your device, and at the same time it gives you a reasonable preview on a low resolution screen. It has since become an industry standard for printing and imaging. Take into account that the average home laser printer is not a Postscript capable printer; which is usually more expensive and more often purchased for business use.
Quad:: Definite interspace on the base of a square. Its side length is equal to the height of the current font.
Refresh Rate:: Refresh Rate is the amount of time a display’s image is redrawn per second. The refresh rate is expressed in hertz. A refresh rate of 75 means the image is refreshed 75 times per second. The refresh rate for each display depends on the video card used. You can change the refresh rate in the display properties of your computer. However, if you change the refresh rate to a setting that the display cannot support, the display goes blank or the image becomes distorted. Therefore, it is recommended to consult the manual before changing the setting in order to determine the supported refresh rates.
Resolution:: Resolution is the number of pixels contained on a display monitor, expressed in terms of the number of pixels on the horizontal axis and the number on the vertical axis. The ratio of horizontal to vertical resolution is usually 4:3, the same as that of conventional television sets. The sharpness of the image on a display depends on the resolution and the size of the monitor. The same pixel resolution will be sharper on a smaller monitor and gradually lose sharpness on larger monitors because the same number of pixels are being spread out over a greater number of inches. A given computer display system will have a maximum resolution that depends on its physical ability to focus light and usually several smaller resolutions. For example, a display system that supports a maximum resolution of 1280 by 1023 pixels may also support 1024 by 768, 800 by 600 and 640 by 480 resolutions. Note that on a given size monitor, the maximum resolution may offer a sharper image but be spread across a space too small to read well.
RGB:: Red Green Blue, the base colours of the additive colour model
rods:: These receptors on the retina enable vision under darker light conditions at around 500nm. They are not responsible for any colour reception. They contain pigments tuned to receive wavelengths in three parts of the visible spectrum that gives us trichromatic vision. Further information can be found on the following page: http://www.yorku.ca/eye/specsens.htm (last updated on 28.5.2003)
saturation:: This attribute describes the intensity of the colour experienced. It describes the tone of a coloured area in relation to the colour’s lightness. This means white is not saturated at all, light-blue is partly saturated and dark blue is very saturated.
scalable screen fonts:: These are fonts which outlines are described by mathematical formulae, permitting them to be shrunk or enlarged to almost any point size. Screen fonts are the representations of fonts that appear on your computer’s screen. Within the realm of scalable fonts, there are several different techniques for generating fonts. Scalable fonts need elaborate "hinting instructions" to look good, which requires much larger fonts and sophisticated rasterizing technology to interpret the instructions. Moreover, the best-hinted TrueType scalable fonts still contain bitmaps for the smallest sizes, because it has turned out to be the best way of hinting them. Paradoxically, bitmap fonts are the ultimate way to hint scalable fonts. Fortunately, for most users, Microsoft Windows provides a technique that is both easy and powerful. These fonts are known as TrueType fonts, with the identification ‘TT’. TrueType fonts are scalable to any size and look exactly the same on the screen as they do when printed. These fonts have a low screen resolution that precipitates the ‘stair-case effect’. Here it is necessary to verify whether or not real antialiasing has occurred or if they were softened, which leads to an macerated look. Advantages of scalable screen fonts to be designated: Small needed disk space Texts stay editable Special sorts of fonts may not be available on all computers per default. Therefore these fonts need to be supplied separately if the screen design should still fit afterwards.
scale:: Scale is the amount of reduction that takes place in going from real world dimensions to the new mapped area on the map plane. Technically, the scale of a map is defined as the ratio of distance measured upon it to the actual distances which, they represent on the ground (ICA 1973).
tracking:: The average space between characters in a block of text. Sometimes also referred to as letter spacing (Adobe).
Transcription:: This is a method of replacing elements, fonts, characters or sounds however they may be written with characters or sounds of another language.
Transliteration:: This is a method of transcription. It describes the replacement of any character in one language, for a character in another language. Here we aspire reversibility. That means – out of a transliterated name, the original one can be reconstructed.
visible spectrum:: Light, along with invisible non-ionising radiation such as radio waves and microwaves, is a form of electro-magnetic energy. Light is distinguished from these other forms of e-m radiation because we can see it and it is defined by this property. Wavelengths between 380 - 700 nanometres are visible to the human eye. Electromagnetic energy below 380 nm is termed ultra-violet (u-v), and that above 700 nm. is termed infra-red (i-r). Both u-v and i-r are absorbed by the media of the eye, and do not generally reach the photoreceptors in the retina. As they are not visible, u-v and i-r radiation is not generally considered to be 'light'. The human lens acts as a u-v filter, and if it is removed (e.g. by a cataract operation) the person can then have an extended range of vision. The absorption of the non-visible radiation can have short-term and long-term effects, causing, for example, snow-blindness and cataracts respectively. The sensitivity of the eye over the spectrum changes with light level. At low light levels, the active photoreceptors of the eye are the rods rather than the cones. Rods have a different spectral sensitivity from that of cones, and consequently, longer wavelengths (reds), tend to look relatively darker at night than during the day, whilst shorter wavelengths (blue) tend to look relatively lighter. Other creatures have different ranges which, make up their visible spectrum, and butterflies can see in ultra-violet, whilst some snakes can see in infra-red. Some 'night-vision' enhancers convert invisible infra-red radiation into visible light by using cameras that are sensitive in this 'invisible' portion of the spectrum. The camera output is then viewed on screens that display the image using a portion of the spectrum that is visible to people.