Digital graphics file formats

1. Digital Graphics
File Formats
Roberta Haslam

2. Raster Graphics
• A raster graphics image is a dot matrix data structure
representing a rectangular grid of pixels, or points of
colour, which can be seen via a monitor, paper, or
other display medium.
• Raster images are stored in image files with varying
formats.
• Are digital images that can be captured by using a
scanner and camera.

3. Raster Graphics
• Raster Graphics are made up of bitmaps, which
is a grid of very small squares. Hence, the
images become ‘pixelated’.

4. Vector Graphics
• Vector graphics is the use of geometrical
primitives such as points, lines, curves, and
shapes or polygons - based on mathematical
expressions - to represent images in computer
graphics.

5. Vectors
Vectors can be shrunk down to a
business card or put on a huge
billboard and will not lose quality of
definition.
Vector graphics are based on vectors (also called
paths), which lead through locations called
control points or nodes.

6. Raster Graphics

7. JPEG
Stands For
Used For/Examples It can be used to save photographs and web images in an
universal format.
Advantages o Most photographs and web images will be jpeg.
o Very universal- a recognised standard format that is
used by everybody.
Disadvantages o It is not the highest quality image you can get because
you can lose information due to compression.
Joint Photographic Experts

8. TIFF
Stands For
Used For/Examples It is used for page layouts, magazines, newspapers and
Photoshop.
Advantages o High quality because TIFF has the option for lossless
compression. Hence, all information is restored.
o Useful for publishing Adobe InDesign documents.
Disadvantages o Large file sizes
o More specialist viewing software
Tagged Image File Format

9. GIF
Stands For
Used For/Examples It can be used for slightly moving animations, often
found on the World Wide Web.
Advantages o Smaller. Hence, less data causing it to download
quicker.
o No interaction needed (standalone).
o Easy to create as they are simple shapes.
Disadvantages You can’t use video clips because it is not supported
using this format.
Graphics Interchange Format

10. BMP
Stands For
Used For/Examples For example, when we set an image in Photoshop to 300
dipi. This allows us to view the image in a better
resolution.
Advantages o Similar to TIFF and JPEG. This may put the user at ease
because they have previous experience with file
formats.
o This file type is not used a lot nowadays, some PCs still
have bmp as an option which is quite useful.
Disadvantages o Limited in its resizing, as image can become distorted.
o Curves are not smooth. Hence, you may find it difficult
to understand as the detail in picture isn’t clear for the
human eye.
Bitmap Image File

11. Vector Graphics

12. PSD
Stands For
Used For/Examples
Photoshop documents can be used to create and manipulate
images.
Advantages
o Image manipulation. E.g. Cut people out of magazines.
o It can be used to edit front cover images for magazines.
Disadvantages o File size can be very large when lots of effects and layers are
added.
o You need Photoshop to look at the images.
o Cannot be uploaded to Facebook/blog etc.
o Not very universal
Photoshop Document

13. AI
Stands For
Used For/Examples It is used as a drawing program to sketch images onto
softcopy.
Advantages o Advanced tools
o Good for logos and big graphical elements.
o Good for creativity
o Graphic designers/ illustrators
Disadvantages
o Very specialist software
o Only viewed with program itself or save it as another file
type.
Adobe Illustrator Art

14. FLA
Stands For
Used For/Examples FLA is used for creating animation and games. Good for
skilled professions such as: web designer/ animator/ game
maker
Advantages
o Can include more advanced sound and video.
Disadvantages o Some browsers need flash to run properly.
o Specialist software.
o Often requires upgrades.
Flash File

15. WMF
Stands For
Used For/Examples Windows metafile is used for logos
Advantages o The photo size can be scaled big and small. This wouldn’t
alter the image as it would always look perfect.
o Can contain both vector and bitmap components.
Disadvantages o “Awful clipart”
o Can be used for small village fair
o Professional graphic designers would use better
software.
Windows Metafile

16. File Format Capture
and Optimising

17. Compression
Definition
Advantages o You can get a good quality image if you use low compression.
o Compression can save storage capacity.
o Uses less communication bandwidth than an uncompressed file.
o Accelerate file transfer - a compressed file needs less time to transfer.
o Reduce costs for storage hardware and network bandwidth.
o A reduction in storage hardware- A compressed file requires less
storage capacity than an uncompressed file.
Is the reduction in the number of bits needed to represent data.
Compression is performed by a program that uses a formula or
algorithm to determine how to shrink the size of the data.

18. Compression
Disadvantages o Images become very pixelated as they are compressed causing
poor image quality.
o When the image is being compressed and decompressed, it can
affect the overall performance because CPU and memory
resources are being used
o Your PC may not be able to scan a compressed file for viruses
causing the computer to become exposed to harmful threats.
o If you need to access file quickly, you will have to wait a long
time because it is a slow process due to processor time.
o Lossy compression reduces the amount of information stored in
your file. Hence, information is misplaced.

19. Good vs Bad Compression
Images become more pixelated as they are compressed causing very pixelated
poor image quality. ( Bad Compression)

20. Image Capture
Method Scanner
How is it used for image
capture of graphics
Scanner can capture images by digitising physical
images such as: sketches, physical photos or mixed
media products.
Method Camera
How is it used for image
capture of graphics
Images can be captured by taking pictures using a
digital camera or phone.
Method Graphics Tablet
How is it used for image
capture of graphics
Images can be captured by camera and then
downloaded onto graphics tablet.
Graphics tablet can be used for drawing or selection of
various images or digital handwriting using the stylus.
This method is very effective because it gives good brush
and different effects.

21. Image Capture
Graphics can be captured by:
 Scanner
 Digital camera

22. Image Capture
• Graphics tablet

23. Optimising
Why would you
optimise?
How can you
optimise?
You can optimise images by changing “Image size” in Photoshop.
Images can be optimised by:
• Reducing image size
• Reducing bit depth
• Reducing resolution
• Compressing images
Advantages of
optimising
o Images on a website should load very quickly. For example, less
than five seconds.
Disadvantages of
optimising
o If images is more than five hundred pixels wide, the image can
become pixelated
I would optimise images before putting them online because it
allows the public to see images in a better resolution.

24. An Example of Optimising Images

25. Storage

26. File Size
What could affect a Working Scale
(Photoshop) document file size?
How could you reduce the file size of a
Working Scale document without
affecting quality?
You can reduce the file size by setting the
document to A4 International paper and to three
hundred pixels.
What is an advantage of scaling up
images before exporting?
Scaling up images before exporting ensures that
image is measured correctly by ruler to fit the
page layout that the image would be exported
to.
What is a disadvantage of scaling up
images before exporting?
The disadvantage of scaling images before
exporting may give you trouble because you may
have to readjust page margins, to measure it
accurately on the document.
If you extend the image width to more than
300 pixels you can distort the image, which
can appear blurry.

27. File Naming Conventions
What naming
conventions could you
use when creating your
video game assets?
• I would use FLA to create video game assets because it can
include sound, animation, games and video which is
applicable for a video game.
Why is it a good idea to
accurately name your
assets?
• It is a good idea to name your assets individually so you
would not have any trouble finding them.
• You can use characters such as: _, *, &, to make your folder
name unique and help to relocate that particular file.
• It is also useful to put the date as Year/Month/Day and
sort files by name because your files would automatically
be in date order.
• If you include the group name before the file name, it
would group them together automatically which would
save you the task of doing it yourself.

28. Asset Management
Why would you use folders when
storing your assets?
What folders would you create
and what would you save within
them
I would create file folders for the different files under
each category.
I would save photos, music and confidential information
within them.
It is important to create folders to store your files or
documents because it helps to keep your work in an
organized manner, so that you can restore them for
future use.
I would also create sub folders within a folder under
different categories. To make locating files so much
easier.