Glossary

Welcome to the glossary of technical terms. Browse through the alphabetic list to find the term(s) you’re looking for.

P

Packet:

A block of data with a known structure, usually used to denote elements of a stream.

Palette:

A thumbnail of all available colors to a computer or devices. The palette allows the user to choose which colors are available for the computer to display. The more colors the larger the data and the more processing time required to display your images. If the system uses 24-bit color, then over 16.7 million colors are included in the palette.

PCX:

A popular bitmapped graphics file format that handles black and white, 2-bit, 4-bit, 8-bit and 24-bit color.

PCMCIA:

An abbreviation for Personal Computer Memory Card International Association. The PCMCIA card eliminates the need to have the camera connected to the PC to record pictures.

PDA (Personal Digital Assistant):

Any of several forms of lightweight, hand-held, computers, usually pointer based, and used primarily as a personal organizer, but increasingly taking on the more sophisticated tasks of a standard PC.

PDL (Page Description Language):

A computer language created by a vendor to communicate with output devices. The most popular page description language in use today is Adobe's PostScript.

Pel:

See pixel.

Peripheral:

A term used to collectively describe computer hardware accessories such as printers, modems, scanners, etc.

PIC:

A standard file format for animation files.

PICT:

A graphics file format used primarily on Macintosh computers. PICT files can contain both object-oriented and bit-mapped graphics. There are two types: PICT I and PICT II. PICT II is the current standard and supports color up to 24-bit.

Pipelining:

This process is used by computer processors to speed up the processing of data. A processor begins executing the next command before the first command has been completed.

Pixel (PICture ELement):

The smallest element of a digitized image. Also, one of the tiny points of light that make up a picture on a computer screen.

Pixels Per Inch (PPI):

A measure of how much detail you see in your images.

Pixel Values:

Numerical data items in a graphics file indicating the color or other information associated with an individual pixel.

Planar Data:

Image data stored as separate color planes and meant to be assembled into the final image by the rendering application.

Planar Files:

Graphics files with image data stored as bit planes or color planes rather than as pixels.

Plotter:

A bitmap rendering of vector or 3D graphical data used to display an approximation of the graphical data. See thumbnail.

Plug-in:

A program extension that adds function to a program without changing the original program.

Plug and Play:

An automated installation process used to connect peripherals to a computer. When new devices are plugged into the computer the computer recognizes the device and prompts the user to choose setup options and finish installation.

PNG:

Portable Network Graphics pronounced ping. A new standard that has been approved by the World Wide Web consortium to replace GIF because GIF uses a patented data compression algorithm. PNG is completely patent and license-free.

PostScript:

A page description language developed by Adobe Systems, Inc. to control precisely how and where shapes and type will appear on a page. Software and hardware may be described as being PostScript compatible.

Predictive Encoding:

An algorithm that has prior knowledge about the format of the data it is encoding. Huffman is a predictive encoding algorithm.

Preview:

A bitmap rendering of vector or 3D graphical data used to display an approximation of the graphical data.

Primary Colors:

Colors that can produce other colors by mixing them together. For example, in the RGB color model, red, green, and blue are primary colors.

Pseudo-color:

A color specified through the use of a palette or look-up table.