|
ANALOGUE - a signal that stimulates sound or vision by electrical analogy e.g.
variations in voltage producing corresponding variations in brightness or vice
versa.
BINARY - counting system using just two digits, 0 and 1, or black or white in
imaging terms.
BIT - short for Binary Digit; a single number having the value 0 or 1. Eight
bits make 1 Byte.
BYTE - standard unit of binary data storage in memory or disc files. Each Byte
contains 8 Bits; each Byte has 256 possible values (28).
CCD - Charged Coupled Device, a solid state image pick-up device or sensor that
produces an output analogous to the amount of light striking each of its picture
elements.
CD-ROM - A form of compact disc used for storing digital data of all types.
CMOS - Complementary Metal Oxide Semiconductor. The second of the most commonly
used types of solid state image pick-up sensors found in today’s digital
cameras. The CMOS sensors are less sensitive than their CCD counterparts and
also consume less power. They are cheaper than CCD sensors.
COMPATIBLE MEMORY TYPE(S) - refers to the type of memory cards a camera uses to
store images on. Most cameras except just one type of memory card but many will
accept multiple formats.
COMPRESSION - a digital process allowing data to be stored or transmitted using
less than the normal number of bits. The common form of data compression being
the JPEG format.
DIGITAL ZOOM - known also as simulated zoom. Digital zoom works by taking a
small portion of an image and enlarging it using interpolation software to give
the effect of an optical zoom. However due to having no moving parts to
physically get closer to the subject digital zooms in their nature are low
quality and limited.
DIGITIZE - to convert into digital form. This process involves sampling the
analogue signal, giving it a numerical value and then coding this number in
binary form. For example a digital photograph or image is made up of grid
points. There is no continuous variation of color or brightness. Each point on
the grid has a specific value. Digital images are recorded as data, not as a
signal.
DIGITAL IMAGING - This is the collective term we use for the process of
digitizing photographs, negatives or slides and then manipulating the image on
screen using a computer.
DPI - Dots Per Inch, the measurement of a printer's resolution - the maximum
number of dots that can be printed per square inch of the page.
FILE SIZE - An image's resolution and dimensions determine it's file size (i.e
how much storage space it takes up). It is expressed in kilobytes (k) or
megabytes (Mb)
GUI - Graphical User Interface: a user friendly computer interface introduced by
Apple and emulated by Microsoft's Windows, which uses symbols (icons) to
represent computer functions. Opening up home computing for the masses, what we
know and see as the face of modern home computing starting with the desktop icon
layouts.
HARD DISK - the term used for either an internal or external rigid disc used for
storing and reading computer data. It's capacity is commonly measured in
megabytes or gigabytes.
IMAGE CAPACITY - refers to the camera's maximum memory capacity with the
supplied memory card for images and video clips stored. This can be varied by
different capacity memory cards.
IMAGE RESOLUTION - the number of dots per inch (dpi) or pixels per inch (ppi).
The higher the number of pixels in an image, the more detailed it is, and
therefore the higher it's resolution.
ISDN - a type of telephone line designed for transmitting digital information.
ISO - is the standard for film sensitivity relative to light levels. ISO 100,
200, 300, 400 etc. Quite simply the higher the number, the greater the
sensitivity the film has to light therefore the higher the number the darker the
lighting conditions it can be used in. Film quality regarding it's grain or
resolution drops the higher the ISO film speed.
JPEG - a widely used method of compressing digitized image data for storage and
transmission.
MEGAPIXEL - the size of the image produced by a digital camera, calculated by
taking height of the image in pixels and multiplying it by the width. The larger
the megapixels the better the image quality
MULTIMEDIA - a collective term used to describe the combination of various media
e.g. sound, text, graphics, video and still photographs - into an integrated
package.
ON-BOARD-MEMORY - some digital cameras have built-in memory instead or as well
as removable media to store images on.
OPTICAL ZOOM - optical zoom works the same as a traditional film camera where
the elements within the lens physically move, reducing and enlarging the field
of view and making the subject appear closer or further away.
OUTPUTTING - the creation of a print, slide, negative or film from one or a set
of digital images or processes. Image quality and size are determined by the
file size.
PHOTO CD - a system developed by Kodak for recording images onto a compact disc.
A system now widely used by photographic processing and printing businesses.
PHOTOSHOP - an industry standard graphics program developed originally and
specifically for image manipulation and graphical design.
PIXEL - a single dot on a computer screen or in a digital image. The combination
of thousands or millions of dots on your computer screen creates the illusion of
an image. A high quality 10x8 inch print would contain around five million
pixels.
RAM - Random Access Memory: temporary memory created when a computer is switched
on. The size of images which can be opened is dependent upon the amount of RAM
installed in the computer.
RAW - usually found on higher end cameras, this picture format uses absolutely
no compression as it is the raw visual information from the camera digital image
sensor. The RAW image format will take up the most memory space and usually
require the specific cameras software to open it up on your computer.
RGB - Acronym for Red, Green and Blue. These are the three basic colors used in
computer monitors to generate color.
ROM - Read-Only-Memory: a memory unit in which data is stored permanently, and
cannot be changed or erased (e.g. a compact disc also known as a CD-ROM).
SENSOR - are the devices that convert light into electronic data. There are two
main types, CCD (charged coupled device) and CMOS (complementary metal oxide
semiconductor). CCD sensors are more expensive but give great fidelity and light
sensitivity. CMOS sensors are cheaper, have less sensitivity and consume less
power. Because digital cameras are often compared to their 35MM film
counterparts, digital camera sensitivity is often rated on the film "ISO"
standard for film sensitivity. ISO 100, 200, 300, 400 etc. The higher the
number, the greater the sensitivity.
SCAN - Means of putting a print or, slide or negative into the computer.
Converting analogue data into digital format.
SCAN RESOLUTION - this is primarily determined by the capability of output
device. To work on an image on screen only, the scan resolution will be that of
the screen.
SCSI - industry standard socket for connecting peripheral devices such as
printers and scanners to computers. This socket is rapidly being taken over by
USB and Firewire.
SYQUEST DISC - high density, removable data storage disc which can be used to
transfer images from one computer to another.
SYQUEST DRIVE - a device used to 'play and record' SyQuest discs.
THUMBNAIL - a small, low resolution version of an image, used for cataloguing,
sorting and finding images.
TIFF - an uncompressed file format that does which produces larger and better
quality files than JPEG format. Tiffs will take up more memory space than JPEG
format.
USB - Universal Serial Bus. An outgoing connector compatible with virtually all
PCs and Apple Macintosh computers made since 2000. USB connections are much
quicker and more user-friendly than a serial port, but it is also a more recent
innovation not found on older computers.
WYSIWYG - (pronounced wissy-wig) stands for 'What You See Is What You Get' and
refers to the relationship between the screen display on the computer and the
final output.
|
