Raster Graphics -JPEG -TIFF -GIF -BMP Vector Graphics -PSD -AI -FLA -WMF Compression Image Capture Optimising

1. Digital Graphics
File Formats
Katy Fleetham

2. Raster Graphics
Raster graphics are made up of bitmaps. Bitmaps
are made up of pixels of a fixed resolution (such
as 300dpi which is often used for Photoshop
documents). Resizing raster graphics can cause
distortion of the images.

3. Vector Graphics
Vector graphics are made up of vectors (or
paths/strokes). They are defined by a start and
end point with curves, points and angles. Unlike
raster graphics, vectors can be scaled with no
loss in definition which makes them ideal for
company logos as they can be used on business
cards and scaled large enough to fit a billboard
without losing image quality.

4. Raster Graphics

5. JPEG
Stands For Joint Photographic Experts Group
Used For/Example JPEG files are most commonly used for
photographs and web formats. Facebook
saves uploaded images in JPEG format.
Advantage JPEG files are often much smaller than
others and therefore take up less memory.
JPEG is also a universal file which can be
opened pretty much anywhere, whether it
be a phone or a computer.
Disadvantage The image is compressed when saved.
Every time the image is saved after editing
it will be recompressed. This means that
less pixels will be saved each time and as a
result the image will appear to lose quality
over time.

6. TIFF
Stands For Tagged Image File Format
Used For/Example TIFF’s are most commonly used for
desktop publishing. Adobe InDesign
documents are often saved as TIFF’s.
Advantage TIFF’s can save multi-page documents in a
single file which is why Adobe InDesign
documents are usually saved in this format.
TIFF files have lossless compression
which means they can be saved multiple
times without losing image quality.
Disadvantage TIFF’s (due to the amount of information
they can store) have rather large file sizes
which can take up a lot of memory. A TIFF
is also a specialist file which means it
requires certain programmes to open the
document, unlike JPEG files which can be
opened almost anywhere.

7. GIF
Stands For Graphics Interchange Format
Used For/Example GIF files are used to store short, digital
animations. A GIF is a series of images on
loop which creates the appearance of a
video.
Advantage A GIF has a reasonably small file size
which means they can be viewed easily
online as they will load quicker and are
still of good quality. GIF’s can also give a
professional look to websites as they can
have transparent backgrounds.
Disadvantage Images may look blocky or pixelated due
to the limited colour palette. This makes
them appear to be of poorer quality. Once
an animation has been saved as a GIF, you
cannot edit it. This makes it very difficult
to make minor alterations to the animation
when it has been saved.
http://stories4all9858697.wordpress.com/2012/12/05/advantages-and-disadvantages-of-using-animated-gifs/

8. BMP
Stands For Bitmap Image File
Used For/Example A bitmap file is similar to that of a JPEG or
TIFF. A BMP can be used to save any
pixel-based images.
Advantage Bitmap files save images which are a high
quality as they have no loss from
compression when they are saved.
Disadvantage Since bitmap images are high quality, this
results in a large file size which can take up
lots of memory.
http://graphicssoft.about.com/od/graphicformats/f/summary.htm

9. Vector Graphics

10. PSD
Stands For Photoshop document
Used For/Example PSD files are used for image manipulation
and magazine front cover images as it is
able to save layers, page formatting
information, swatches ect.
Advantage PSD supports transparency so images can
be saved without a background. Also, since
PSD can save layers, this makes it easy to
go back and edit the file later on if needs
be.
Disadvantage The file can only be opened in Photoshop
and by some Adobe programmes. Due to
the amount of information and layers that
the document can recall, it takes up a lot of
memory as a large file.

11. AI
Stands For Adobe Illustrator Art
Used For/Example AI is used to create graphics which can
represent a company (such as a logo).
Advantage The images can be scaled smaller or larger
with no loss in definition so images can be
of high quality.
Disadvantage An AI file requires specialist software to
open which limits where it can be viewed.

12. FLA
Stands For Flash file
Used For/Example Flash files are used to create animations
and games.
Advantage FLA files are high quality, but they only
have a small file size, which makes them
good for the web as they wont take long to
load. A flash file can include both videos
and sound.
Disadvantage A limited amount of software can open a
FLA file as it is a specialist file.

13. WMF
Stands For Windows Metafile
Used For/Example Similar to AI files, WMF files are used for
logos and company graphics. WMF is a
windows format used mainly for clipart.
Advantage The images saved as WMF’s can be scaled
smaller and larger with no loss in definition
and this file can contain both bitmap and
vector components.
Disadvantage A WMF is only available on windows
platforms so they can only be generated on
these.
http://www2.sas.com/proceedings/sugi23/Begtutor/p54.pdf

14. File Format
Capture and
Optimising

15. Compression
Definition Lossy compression is a reduction in the
file size which is caused by reducing the
amount of information which is saved.
Advantage The main advantage to compression is that
it reduces the file size and the amount of
memory in which the file requires.
Disadvantage When compressed, images lose quality and
appear more pixelated because less pixels
are saved each time.

16. Image Capture
Method Scanner
How is it used for image capture of
graphics
A scanner is used to digitalise physical
images (eg, from a drawing to a photoshop
document). “The basic principle of a
scanner is to analyze an image and process
it in some way.”
http://computer.howstuffworks.com/scanner.htm
Method Camera
How is it used for image capture of
graphics
Light enters the lens of a camera and is
recorded by a sensor, the sensor records
information for all the pixels which then
produces an image (digital).
Method Graphics Tablet
How is it used for image capture of
graphics
Some tablets have technology which
allows you to control a mouse like a pen
for illustration and other purposes.

17. Optimising
Why would you optimise? Images which are uploaded to the
internet are optimised for easy viewing
on the web.
How can you optimise? You can optimise images for the web by
changing the “Image Size” in Photoshop.
You can optimise by: reducing the image
size; reducing the bit depth (regarding
pixel colour); reducing the resolution; and
by compressing images.
Advantage to optimising By optimising an image, you reduce the
file size, which means it downloads faster.
Disadvantage to optimising Optimising an image reduces the amount
of pixel information, usually until images
are no more than 500 pixels wide.