Reply to Definition Questions
7th Sign – please answer the previous post before creating your own.
CD ROM - Compact Disk, Read only Memory.
A type of optical storage device, capable of storing up to 650Mb of data. The data stored on CD-ROMs is static, and cannot be changed.
The data is stored on a plastic disc coated with a metallic reflective surface, on which are indented pits and raised lands. A laser in the CD drive reads these pits and lands and interprets them as biary data.
*DVD
Digital Versatile Disk
A similar optical storage device to a CD-ROM, except that many DVD's have dual or even triple layers of storage. When created, Data can be stored on any or all of these layers - this means that DVD's can store up to 4.7Gb of data, considerably more than a CD-ROM. The major advantage of the DVD is that all data is stored using the same file format, called UDF (Universal Disc Format.) - this overcomes problems of incompatability that CD's often encounter. (NB: When talking about S+E issues and DVD's, make sure that you mention region codes on players and discs.)
*Firewire
FireWire is Apple Computer's version of a standard, IEEE 1394, High Performance Serial Bus, for connecting devices to your personal computer. FireWire provides a single plug-and-socket connection on which up to 63 devices can be attached with data transfer speeds up to 400 Mbps (megabits per second). The standard describes a serial bus or pathway between one or more peripheral devices and your computer's microprocessor. (NB: Definition from
http://whatis.techtarget.com. Firewire is not on the syllabus, so don't kill yourself over this one.)
*CRT
Cathode Ray Tube. A display device for computer systems. A CRT displays images by firing electrons onto the inside of a phosphor-coated screen. This phosphor is laid out in tiny rows and columns, the intersection of which is called a PIXEL. Monochrome monitors use only one electron stream for one colour. Colour monitors use three streams at different intensities to blend the primary colours, (Red, Green, Blue.) to create different hues and shades. (You might also want to refer to Raster and Vector scanning… but I’ll leave that to the next post.)
NB: Higher-end CRT’s used four electron streams, CMYK, Cyan, Magenta, Yellow and Black. Taken out of production with introduction/development of the LCD.
*LCD
Liquid Crystal Display. Also a display device for computer systems. They consist of a layer of liquid crystal (LC) sandwiched between two plates of thin polarized glass. Light is passed through the LC, and an electronic current is applied at certain locations to create the image. LCDs are light, take up less space than a CRT, emit less heat and radiation, and require less power than CRTs. However, picture quality is somewhat reduced, but will increase as the technology is developed.
*DLP
Digital Light Processor. A newer, more expensive scheme for data projection (over the three-LCD projectors) is known as Digital Light Processing (DLP), a proprietary technology developed by Texas Instruments. In a DLP display, tiny mirrors are used instead of transparent LCD panels. Each mirror represents one pixel. The light, rather than passing through the panel, is reflected from it. The mirrors move back and forth, varying the amount of light that reaches the projection lens from each pixel. Color is obtained by passing the light from the lamp through a rotating wheel with red, green, and blue filters. This subjects the mirrors to light at each of the primary colors in a rapid rotating sequence. The result is a color-modulated image that the human eye sees as natural color. Advantages of DLP technology include light weight, high contrast, and lack of pixelation.
*WYSIWYG
A WYSIWYG (pronounced "wiz-ee-wig") editor or program is one that allows a developer to see what the end result will look like while the interface or document is being created. WYSIWYG is an acronym for "what you see is what you get". A WYSIWYG editor can be contrasted with more traditional editors that require the developer to enter descriptive codes (or markup) and do not permit an immediate way to see the results of the markup. The first true WYSIWYG editor was a word processing program called Bravo. Invented by Charles Simonyi at the Xerox Palo Alto Research Center in the 1970s, it became the basis for Simonyi's work at Microsoft and evolved into two other WYSIWYG applications called Word and Excel.
An HTML WYSIWYG editor, such as Microsoft's FrontPage or Adobe's PageMill conceals the markup and allows the Web page developer to think entirely in terms of how the content should appear. One of the trade-offs, however, is that an HTML WYSIWYG editor sometimes inserts the markup code it thinks is needed all on its own. Then, the developer has to know enough about the markup language to go back into the source code and clean it up.
*AVI
An AVI (Audio Video Interleaved) file is a sound and motion picture file that conforms to the Microsoft Windows Resource Interchange File Format (RIFF) specification. AVI files (which end with an .avi extension) require a special player that may be included with your Web browser or may require downloading.
*JPEG
JPEG (usually pronounced JAY-pehg) is also a term for any graphic image file produced by using a JPEG standard. A JPEG file is created by choosing from a range of compression qualities (actually, from one of a suite of compression algorithms). When you create a JPEG or convert an image from another format to a JPEG, you are asked to specify the quality of image you want. Since the highest quality results in the largest file, you can make a trade-off between image quality and file size. Formally, the JPEG file format is specified in ISO standard 10918. The JPEG scheme includes 29 distinct coding processes although a JPEG implementor may not use them all.
*TIFF
TIFF (Tag Image File Format) is a common format for exchanging raster graphics (bitmap) images between application programs, including those used for scanner images. A TIFF file can be identified as a file with a ".tiff" or ".tif" file name suffix. The TIFF format was developed in 1986 by an industry committee chaired by the Aldus Corporation (now part of Adobe Software). Microsoft and Hewlett-Packard were among the contributors to the format. One of the most common graphic image formats, TIFF files are commonly used in desktop publishing, faxing, 3-D applications, and medical imaging applications.
*PDF
PDF (Portable Document Format) is a file format that has captured all the elements of a printed document as an electronic image that you can view, navigate, print, or forward to someone else. PDF files are created using Adobe Acrobat, Acrobat Capture, or similar products.
PDF files are especially useful for documents such as magazine articles, product brochures, or flyers in which you want to preserve the original graphic appearance online. A PDF file contains one or more page images, each of which you can zoom in on or out from. You can page forward and backward.
*EBCDIC
EBCDIC (pronounced either "ehb-suh-dik" or "ehb-kuh-dik") is a binary code for alphabetic and numeric characters that IBM developed for its larger operating systems. It is the code for text files that is used in IBM's OS/390 operating system for its S/390 servers and that thousands of corporations use for their legacy applications and databases. In an EBCDIC file, each alphabetic or numeric character is represented with an 8-bit binary number (a string of eight 0's or 1's). 256 possible characters (letters of the alphabet, numerals, and special characters) are defined.
IBM's PC and workstation operating systems do not use IBM's proprietary EBCDIC. Instead, they use the industry standard code for text, ASCII. Conversion programs allow different operating systems to change a file from one code to another.
Feel free to comment/criticise/edit.
QUESTION:
Define the terms MORPHING and WARPING. Give Examples.
