Multimedia Glossary

Cast: In Film and TV "cast " is used for the actors and extras. In Macromedia Director "cast" includes all the objects (i.e. text, graphics, sound, video, or Lingo scripting behaviors) used in a production. An object needs to be identified as a cast member before it can be used.
In terms of function the Director cast is similar to the Flash symbol library.

CERN: Conseil Européen pour la Reserche Nucléaire; The European Laboratory for Particle Physics is the birthplace of the World Wide Web, the institution where Tim Berners-Lee served as consultant when he created HTTP and HTML. CERN httpd was written by Ari Luotonen, Henrik Frystyk and Tim Berners-Lee.

CGI: Common Gateway Interface; CGI is a method allowing data from client computing devices to pass into a server for processing. CGI is typically used for capturing data sent with web forms to servers.

Character Set: There are tens of thousands of characters used in human writing systems. Unicode lists about 40'000 of these characters. On 8-bit PCs only 128 characters can be mapped to machine code, definitely not enough to handle all these characters. The Unicode characters are divided into sets of characters. A PC needs to be set up to use a particular set. Documents that are distributed over the internet need to specify in which character set they are written so that devices that receive them can render them correctly by first adapting to the specified character set.

Chroma: Chroma is also known as saturation or intensity, and refers to how much of the same hue is present in a color. It refers to the "brightness" of a color. When a primary color is added to, or substracted from itself, its chroma is changed. A color is fully saturated when no other color, no white or no black is added to it.

The primary color blue becomes peacock blue if its chroma is increased, while it becomes navy when its chroma is reduced.

c-HTML: Compact HyperText Markup Language; W3C NOTE 09 Feb 1998; Small devices (such as cell phones and PDAs) have hardware restrictions such as small memory, low power CPU, small or no secondary storage, small display, mono-color, single character font, and restricted input method (no keyboard and mouse). These devices therefore cannot handle traditional HTML web pages. c-HTML was introduced as a scaled-down version of HTML, containing what is regarded as core HTML. Apart from scaling down the variety of typical HTML features, the following HTML features are excluded from c-HTML:; c-HTML has been replaced by XHTML, which is a modular XML-compliant version of HTML.

Client: A client is a device that receives data or programs from a server. This device may be a different computer, or a 'virtual' computer inside a physical computer.

CMYK: Cyan, Magenta, Yellow, K (for Black); The CMYK color scheme is a substractive color scheme where a color is substracted from white light. This scheme is commonly used for devices such as printers because printer inks can be easliy manipulated by removing some hue. By combining certain color hues, the resulting color is absorbed, and thereby prevent it from being reflected by white.

Codec: Communications engineering; Acronym for coder/decoder; In communications engineering Codec refers to the analog-to-digital conversion and digital-to-analog conversion functions that are built into in a single chip.; Video compression; Acronym for compression/decompression; In video compression Codec refers to a software algorithm that eliminates redundancies in data. It throws away bytes according to the criteria of the different available codec systems and thus result in smaller file sizes.

Coded Description
MPEG-7: A Coded Description is a Description that has been encoded to fulfil relevant requirements such as compression efficiency, error resilience, random access, etc

Color: The physics of color is made up of a subset of the electromagnetic spectrum which, when combined, shows as white. Human eyes are physiologically adapted to view such rays, when they are reflected from objects, as colors.

On CRT screens (such as computer or TV screens) electron beams light phosphors of three different frequencies: red, green and blue. The color palette is divided into hues of red, green and blue (RGB).

Markup languages
In markup languages color can be described with values indicating more specific frequencies within these three basic ranges. In HTML there are three methods for describing a color:; In Graphics application programs there are typically be more methods available for describing color hues than just the RGB method, such as CMYK and HSB.

Color depth: or bit depth, refers to the number of bits used to describe the color of a pixel. The color depth of 24-bit color would be 24 bits.
Also see color map, direct color.

Color map / color palette / indexed color: A color map or color pallete is a predefined list of colors with their values. This method is used when colors do not exceed 256 colors. For more colors the palatte becomes too large, and a direct color method is preferred.; Also see Direct color

Content type: Content type is a technical term (following RFC2045 and RFC2046) used for describing the content of a web document so that a user agent can handle the content properly.
Web documents can be sent via different protocols such as HTTP or email (SMTP).
In the Web environment the term Mime type is used.; Also see MIME type and Media type

CRT: Cathode-Ray Tube; A CRT screen is a display unit of which the phosphorous surface is lit by an electron beam in different frequencies resulting in three different color hues: red, green and blue. This is typically the method used for creating images on a computer or TV screen.
Other methods are used for LED (Light Emission Display) and plasma screens.

CSS: Cascading Style Sheet; CSS is a style sheet language based on DSSSL conventions. The function of CSS on the Web is to describe the appearance of visual documents, or the manner in which a speech synthesizer should render them. A markup language (such as HTML, or an XML-based language) marks the logical structure of document content, while CSS describes what the document should look (or sound) like.

Multimedia Glossary: C