2. Digital images
Digital images can be broken into two categories,
artificial or natural.
A natural image is something like a photograph or a
scanned picture. This is where the image is
digitalized by the computer to read then stored or
manipulated.
Artificial images or graphics are images that have
been on the computer using software or other
computer processors.
3. Vector images
Vector images are created on the computer to
by using mathematic algorithms to create
basic shapes, lines and arcs and such. These
shapes are used to make shapes. These can be
manipulated, resized or warped without loss
of resolution or quality.
4. Raster imager
Rasters, also called bitmap, are images made
on a computer using pixels. Pixels are
arranged in grids where they combine colours
and tones to produce a picture or graphic.
Raster imaging is best suited for complex or
photos. The main issue that is presented by
raster images is that they are highly
dependant on their resolution, meaning that
alteration is difficult without changing the
resolution somehow.
5.
6. Image file format
All files on a computer takes a certain form of
a specific format. These different formats
allow the computer to determine what the file
contains, i.e. picture, word doc., shortcut, etc.
When the file is saved it automatically adds a
four letter code that identifies what format
that the file has been saved as.
7. .Jpeg
.Jpeg stands for Join
Photographic Expert Group
and is the most common file
format for pictures and
images. This format is best
suited for images that have
shading or any slight
changes in colour and
lighting effects. This format
unfortunately loses quality
when altered.
8. .Gif
The term .Gif stands for Graphic
Interchange Format. This format is
cross platform and compressed. It’s
limited to a colour depth of 8 bits
(256 colours) and, unlike .jpeg, will
allow some colours to be
transparent. This format uses a
Lossless compression scheme that
allows it to be manipulated without
affecting the quality, the lossless
scheme .gif’s use is called LZW. This
‘no loss’ of quality allows good
quality pictures to be compressed
and shared on the internet without
loss of quality.
9. .TIF
.TIF is a common format used
when images and graphics need to
be used by devices other than the
computer. This allows images to be
accessed through things like
printing devices without the
control of a computer, it is
commonly used for printing things
such as logo’s. This format uses the
same compression scheme as .gifs,
it has very high resolution but is
not ideal for sharing on the
internet.
