2. Raster Graphics
Raster graphics are images that are
constructed of square shaped pixels of
many different colours. Raster graphics
are captured e.g. by a camera, scanner
etc. Or created in an image creation
software and the image’s information
is mapped across a grid meaning that a
raster graphic cannot be edited
without a loss of quality for instance if
you were to attempt to upscale a
raster graphic (right) the original
already has a fixed resolution and
therefore when upscaled a clear loss of
quality can be observed.
3. Vector Graphics
Vector graphics are constructed of
paths and lines (as appose to pixels),
some curved some straight. These
paths and lines contain the data of
where each point starts and end and
also, if necessary, how much they
curve as well as the colours that
surround or take up the line. Due to
the fact that the images are
constructed of lines and paths as
appose to pixels they can be freely
transformed without loss of quality as
they do not have any fixed
characteristics therefore when up
scaling a vector graphic there is no
loss in quality as the data in the
image will fit to the new conditions it
has been given.
5. JPEG
Stands For Joint Photographic Group
Used For/Example JPEG’s are quite commonly used in photography as
cameras typically have the option to shoot in JPEG or
RAW.
JPEGs are also a very popular choice for websites as
their file size is such a small amount meaning that
slower connections are able to download this image
and therefore experience the website a lot faster.
Advantage When JPEG’s are shot on cameras they do not require
specialist software but rather just a simple file that can
be opened, transferred etc. with ease
Smaller file sizes so can be easily accessed online with
a slow connection and created due to the more
available space.
Disadvantage Loses quality very easily so they cannot be
edited multiple times.
Fixed statistics such as resolution making
this a very restricted file type
6. TIFF
Stands For Tagged Image File Format
Used For/Example TIFF is an image file format used when transferring
raster graphics through different applications for
instance faxing: An image is scanned on the first
machine to which it is stored on a TIFF and printed out
on the other machine. TIFF’s are most commonly used
in: Website/Desktop publishing, faxing (as mentioned),
photography etc.
Advantage -Does not perform compression meaning
quality is not compromised during edits.
-Multiple documents can be stored on a single
file.
-Recognised by the vast majority of editing
software's
Disadvantage -Due to the absence of compression the
file types tend to be on the larger side
meaning this file type is less popular to
people with less free space.
7. GIF
Stands For Graphics interchange Format
Used For/Example A GIF is a collection of images that play one after the
other to create a form of video/animation much like the
way a film works by playing many frames.
GIF’s are most commonly used on the internet on social
media, however they are used in a more professional
environment for instance product illustrations tend to
use GIF’s in order to demonstrate how said product will
function.
Advantage -GIF’s are a smaller file size meaning they
can be used as an alternative to videos on
websites for people with a slow download
speed.
-GIF’s are also supported by all web
browsers.
Disadvantage -GIF’s are heavily compressed meaning
quality is always degraded
-GIF’s are restricted to 256 colours meaning
a more complex image will appear
significantly different
8. BMP
Stands For Bitmap Image File
Used For/Example A bitmap is composed on square pixels known
as bits which contain colour information and are
at a fixed resolution (left). Bitmap graphics are
very out-dated and were used on older PC’s and
websites by developers
Advantage -Easy to use in scenarios in which an image
is not to be rescaled or resized such as
PowerPoint presentations, websites etc.
Disadvantage -Fixed resolution meaning rescaling
degrades quality meaning edits cannot be
performed without the loss of quality.
-Larger file size as the computer has to
store the image of each bit.
10. PSD
Stands For Photoshop Documents
Used For/Example PSD files are the format in which a
Photoshop project is saved. Photoshop is
used for image manipulation for projects
such as magazine covers, digital art etc.
Advantage -Multiple layers, effects etc. are saved in
one file.
-PSD’s supports transparency
Disadvantage -Only recognised by Photoshop and
nothing else
-If a project uses many layers and effects
the file size can become very large.
11. AI
Stands For Adobe Illustrator
Used For/Example An AI is the same concept as a PSD but for Adobe
Illustrator as appose to Photoshop. Adobe Illustrator is
used to create vector images which are often used for
company logos, charts, graphs etc. Meaning this file
type is most commonly used for business purposes as
appose to personal
Advantage -Uses vector based images meaning
rescaling, recolouring and general edits
can be performed with no loss of quality.
-Multiple edits can be saved in one file as
appose to many.
Disadvantage -To create this file you need to use Adobe
Illustrator which requires specialist
software.
-File can only be read by Adobe Illustrator
meaning it’s diversity is extremely limited.
12. FLA
Stands For Flash File
Used For/Example Flash Files are used to create multiple
media such as videos and game which are
most commonly seen on the internet
meaning web and or game developers are
most likely to use this file.
Advantage -Flash files can include audio as well as
just visual.
-If made correctly flash files create a high
quality, professional looking product.
Disadvantage -Cannot be edited once created
-Flash files are only accessible via
computers as appose to mobile devices
which are significantly more popular
-When used online the page tends to load
a lot slower
13. WMF
Stands For Windows Metafile
Used For/Example Windows metafile’s were created by
Microsoft for their computers throughout
the 90s. These are rarely used today but
were used mainly by users of Microsoft PC
in the 1990’s.
Advantage -Due to Metafiles being code based they
require less memory than bitmaps (which
were also mostly used at this time).
-The vast majority of metafiles were vector
based as appose to raster based.
Disadvantage -Incredibly out-dated today as images can
be simply constructed in image editing
software.
-Supported by few software in the 90s and
almost none today.
15. Compression
Definition Compression is when an image is resized
or altered in any other way which means
the information from the image is
“compressed” which can cause the loss of
the previous information and thus a
lower quality picture.
Advantage If an image is compressed successfully it
means it will have a much smaller file size
depending on the amount of compression
that has taken place which in itself brings
in many separate benefits depending on
the project.
Disadvantage If the image is not a vector based graphic the
compression will remove the image’s overall
quality which will not be able to recovered. For
example Microsoft Paint is bitmap based and as
mentioned earlier raster graphics do not re
create the image information like vector
graphics (left).
16. Image Capture
Method Scanner
How is it used for image capture of
graphics
Scanners use both mirrors and a lamp to capture the image.
Firstly an image is placed in the scanner and the cover closed to
which it is “scanned” by the scanner head which is made of two
mirror, the first reflects the image into the other and the second
reflects the image into the capture device. A scanner is often
used to transfer hard paper documents to a digital format which
an efficient way of cutting corners in terms of time and is
commonly used for business and or artistic purposes.
Method Camera
How is it used for image capture of
graphics
When the button is pressed on a digital camera an aperture
opens up to which light is brought in and reflected through a
mirror onto the digital capture device (which is the same as the
one used in a scanner) called a CCD. Cameras are used
professionally by photographers but to capture media camera’s
can be used to capture papers images such as drawings in order
to transfer them to a digital format
Method Graphics Tablet
How is it used for image capture of
graphics
A graphics tablet is touch screen based and can be either wired or wireless.
When using a graphics tablet a stylus is required which the user draws an
image on the tablet that appears on the computer screen. These are used as
a form of digital substitute to paper as it cuts out having to transfer the
image to a digital format, working digitally also opens up many doors in
terms of enhancements when creating images.
17. Optimising
Why would you optimise? Optimising images are most often used for web images in
order to enhance quality and file sizes, another important
aspect is file types as if the wrong file type is used the
stability and speed of the website will drastically decrease
which is more than likely to reduce the amount of visitors
to the website.
How can you optimise? Firstly in terms of size images must be saved at the desired
dimensions that they will be posted on the website with as if they are
not it will make the website “heavier” in terms of content thus causing
slower loading times. Secondly files must be one of three file types
which are JPEG, GIF and PNG as these files can be easily compressed
for the internet. The three file types are used for different purposes
which are JPEG’s being still images, GIF’s being a collection of images
played back and finally PNG’s for images with transparent
backgrounds.
Advantage to optimising -Optimising images will give a website a very much more stable
and fast experience which will potentially result in more visitors.
-Image optimisation results in a website have a much more
organised and professional appearance as the sizes and file
types will be correct.
Disadvantage to optimising -Optimising an images size has to be saved at the ideal
dimensions otherwise it will slow down the website which
means extra time is added to a websites development due to
specific dimensions being required.
-The three file sizes that are recommended are compressed for
use online which can result in degraded quality.
