Glossary A-J

acceptable tolerance:
In the blob compressor, the acceptable tolerance is the amount of variation allowed between equivalent blobs in the clustering process.

Describes a color aberration due to heterogeneous pixel spacing. For example, if it occurs in the sampling, due to harmonics between the sampling and event frequencies, it is known as a Johnson alias. On a monitor, it is more likely due to inductive ringing in the monitor cable.

application service provider (ASP):
An Internet server operator that end users to run one or more programs on the Internet or associated server.

The process or act of running a program on a network or associated server.

A special characteristic of text character (such as Bold or Italics).

batch mode:
A computer process that runs without user assistance.

beta mismatch:
A mismatch between two semiconductors (usually transistors) where the same bias results in different amounts of conductivity.

A description of a two color image. For example an image that has black and white but no shades of gray.

The smallest data element inside a computer. It has two states which are denoted as a 1 and a 0.

bit map:
[First Definition] A method of storing an image by using a single bit to represent one of two colors (usually black and white).

[Second Definition] A non-proprietary file format that (in most cases) saves each color of each pixel as one byte. The file extension is usually *.BMP.

A group of adjacent pixels that are all exactly the same color. A blob is sometimes used synonymously with region, but a region is often used as a group of adjacent pixels that are combined together. A region contains the implication that the pixels may not all be exactly the same color.

For example, a region might be used to refer to the entire area of a light gray can sitting on a black background (the background would not be part of the region). The light gray can might have slightly darker gray decorations, but the whole would still be in the same region.

blob compressor:
A proprietary raster compressor that is built into Pac-n-Zoom. It is a geometrical compressor with hierarchical ordering.

A place where one color stops and another color starts. A border implies an abrupt change whereas a transition doesn't.

charge coupled devices (CCD):
These are also known as charge coupled semiconductors. They are semiconductors that are specially fabricated to detect light. They are the sensors used in cameras and scanners to change light into electricity. On this site, the issues presented by CCDs are considered to be the same as those from light diodes and CMOS sensors.

chromatic aberrations:
Optical systems have an exact focus at a specific wavelength of light. Since light usually has more than one wavelength, distortions occur because the light does not match the exact wavelength the optical system is focused at. Therefore chromatic aberations are essentially aberations resulting from different colors (or wavelengths) of light.

clock coupling:
An electronic noise that mixes the clock signal into another signal. This usually occurs from inductive and capacitive coupling between traces on a circuit board or integrated circuit. The affect is compounded because the rising edge of the clock can cause many transistors to switch simultaneously.

In the blob compressor, a cluster is a constellation of patterns that repeated within the acceptable tolerance.

color bleeding:
In printing and other real processes, color bleeding is considered a problem. It is when two adjacent colors get mixed together. In the virtual world, color bleeding is often a desired effect.

color flutter:
A noise that occurs because the color shade is half way between two discrete values and the color presented vacillates between those values. As an analogy, a digital speedometer has flutter when the car is going 54.5 miles per hour, and the speedometer vacillates between 54 and 55.

color segmenter:
A major part of the Pac-n-Zoom program. The color segmenter segments a color while image enhancing the quality of the picture by performing image restoration.

comma delimited file:
[First Definition] A file whose data records are delimited by commas. These are used primarily by spread sheets and databases.

[Second Definition] A non- proprietary file format supported by Pac-n-Zoom and has an extension of *.CDL. It is easily parsed into databases for the purposes of debug.

command line interface (CLI):
A text based interface where the user enters commands at a prompt (such as a DOS prompt).

The initial user command is interactive, but the interface can be manipulated into a batch processing mode.

continuous tone:
A term used to describe an image whose color is constantly changing. The implication is that each pixel is a slightly different color than the preceding pixel.

contour line:
A term used to describe the visible edges of a blob. Contour lines are often used in negative sense to describe a photograph that doesn't have enough colors.

The amount of color change divided by the number of pixels. Therefore, large and fast color changes have a high contrast.

A device that integrates data, instructions, libraries, or other elements over a series of iterations.

dark current:
Thermodynamic noise in a charged coupled device.

data resolver:
A Pac-n-Zoom filter that eliminates repeating single pixel vacillations on the edges of segmented blobs. It is incorporated into the segmenter. The data resolver is incorporated inside the blob compressor.

data segment:
A group of data inside a frame as shown in the following example.

data tagger:
The part of the Pac-n-Zoom technology that converts raster into primitive vector.

data tagger configuration:
A non-von-Neumann computer that has two parts. The first part is called the data tagger and it passes judgments on incoming data. These judgments become instructions and are passed to a convolver. The convolver is usually a conventional (von Neumann) computer or a state machine that accepts separate data and instructions.

depth of field:
Optics will focus at some specific distance. The depth of field will indicate how well a specific part of a picture will focus by how far it varies from the focal point.

discreet cosine transform:
The discreet cosine transform converts spatial information to "frequency" or spectral information, with the X and Y axes representing frequencies of the signal in different dimensions. This allows for "lossy" compression of image data by determining which information can be thrown away without compromising the image.

The DCT is used in many compression and transmission codecs, such as JPEG, MPEG and others. The pixels when transformed are arranged from the most significant pixel to the least significant pixel. The DCT functions themselves are lossless. Pixel loss occurs when the least significant pixels are quantitized to 0 (from

A wavelet-based (but uses other technologies as well) technology originally be Bell Labs (AT&T). In 2000, DjVu was acquired by Lizard Tech.

document handling:
An industry that deals with moving paper files to the computer.

document imaging:
A subset of the document handling industry that deals with converting the document from a paper to an electronic representation.

edge detection segmentation:
Segmentation that finds the edges of blobs to build a border around the blob.

The process of pulling information from a picture. The information could be any thing. Some typical extractions are recognition, location, color, area, and perimeter.

Any parameter of an image. Some typical features are edges, colors, areas, and locations.

The style of text character (such as Courier or Times Roman).

A set of data that pertains to a configuration, data, or command. Frames are found in text files. The syntax or example of a frame can be found here.

frame grabber:
An electronic device (usually a computer board) that stores at least one video frame.

geometrical compressor:
A compression algorithm that reduces geometrical shapes into a more efficient representation (usually tags). Geometrical compressors are not currently popular because they require a segmented image to provide competitive compression.

A proprietary statistical compressor with its name (GIF) used as the file extension.

The glider is the part of the Pac-n-Zoom system that promotes the primitive vector into the final output. The final output might be raster or another form of vector.

graphical user interface (GUI):
An interactive user interface usually dominated by a mouse, track-ball, or some other pointing device. In the predominant interaction, the user points at a screen icon and clicks a button to select the process the icon represents.

An abbreviation for high definition television. It is the high definition television signal mandated in the United States. It is 1,080 lines and has 1920 pixels in a line.

heap memory:
When memory is dynamically allocated by the programmer (usually with a variation of malloc() and free()), the allocated memory is from the computer memory system known as the heap. The heap is allocated at run time.

A graph that plots the most predominant colors against a spectrum of colors.

An abbreviation for hypertext markup language. It is the publishing language of the world wide web. In other words, it is the standard format for an Internet page.

Huffman encoding:
A statistical compression method that converts characters into variable length bit strings. Most-frequently occurring characters are converted to shortest bit strings; least frequent, the longest. Compression takes two passes. The first pass analyzes a block of data and creates a tree model based on its contents. The second pass compresses the data via the model. Decompression decodes the variable length strings via the tree. (from

image restoration:
The process of rebuilding a picture that was distorted by a known process.

Interlaced Video:
Video that is created by interlacing (interweaving) to consecutive pictures to create a single picture.

In interlaced video, the first field is painted into every other line of the video display screen. The second field is then painted into the lines left blank.

interleave file format:
A non-proprietary raster file format that is popular on the Amiga Computer. The file name extension is *.IFF.

Johnson noise:
An electronic noise with a thermodynamic origin. The voltage of Johnson noise is white noise with a voltage squared noise spectral density.

joint photographers expert group (JPEG):
A standards committee that published a file format used for compression. The most popular version of it uses a discrete cosine transform to discard (hopefully) less significant colors.

A common file name extension for JPEG files is *.JPG.