Computer graphics involves using computers to generate and display digital images. It uses both specialized hardware and software to represent image data through computer programs. There are two main types of digital graphics - raster (bitmap) graphics composed of pixels, and vector graphics composed of shapes. Raster graphics tend to have larger file sizes and lose quality when resized, while vector graphics have smaller file sizes and can be resized without quality loss. Common file formats for each type include BMP, JPEG, and PNG for raster graphics, and AI, EPS, and SVG for vector graphics.

2.  Computer graphics is the use of computers to define,
store, manipulate, generate and display images.
 It is about how to program a computer to generate
photo-realistic images.
 Computer graphics are graphics created
using computers and the representation of image data
by a computer specifically with help from specialized
graphic hardware and software.

3. Graphics is cool
I like to see what I’m doing
I like to show people what I’m doing
Graphics is interesting
Involves simulation, algorithms,
architecture…
Almost no area in which graphical displays
cannot be used

4. Many of the leading
scientists through the
ages have been ‘visual
thinkers’…
-Leonardo da Vinci
-Einstein
-Clerk Maxwell

5. Passive Graphics
An interactive computer
graphics user have some
control over the picture
i.e user can make any
change in the produced
image.
A computer graphics
operation that transfers
automatically and
without operator
intervention. Non-
interactive computer
graphics involves one
way communication
between the computer
and the user.
Interactive Graphics

6. Image processing
Rendering
Modeling
Animation

7. Types of image
Raster, Vector and file extensions

8. Types of images
• Raster
• Vector
• Compression
– Lossy
– Lossless

9. Types of digital graphics
• Vector images
- Uses points, lines and curves
- When scaled up there is no
loss of clarity
- E.g: psd, wmf, fla, ai
• Raster images
- Based on pixels
- When scaled there is a loss of
clarity
- E.g: bmp, gif, tiff, jpg
Raster

10. Compression
• Lossy- reduces the size
of the file but also
looses quality.
• Lossless- reduces the
size of the file but the
quality stays in tact.

11. A Bitmap or Raster graphic
• Taking photographs using a
digital camera or scan an
image from a magazine -
creating a bitmap graphic.
• A bitmap graphic is
composed of many tiny
parts, called pixels, which
are often many different
colors.

12. A Bitmap or Raster graphic
• It is possible to edit each
individual pixel.
• Since the computer has to store
information about every
single pixel in the image.
• The file size of a bitmap graphic
is often quite large.
• When you resize a bitmap
graphic, it tends to lose quality.

13. What are vector graphics?
• Vector graphics are
created in graphics
packages and consist of
shapes called objects.
• It is possible to edit each
object separately, for
example, change the
shape, colour, size and
position.

14. What are vector graphics?
• Even if an object in a vector
graphic is quite large, it doesn't
need a lot of computer memory.
• Therefore the file size of a vector
graphic is often very small.
• Vector graphics are scalable - ie
when you resize them, they do not
lose quality.

15. File Types used in graphics
• .bmp,
• .png,
• .gif,
• .jpg,
• .Psd
• .tiff

16. Tiff files ending in .tif
• stands for Tagged Image File
Format.
• TIFF images create very large file
sizes.
• TIFF images are uncompressed
and thus contain a lot of detailed
image data
• TIFFs are also extremely flexible
in terms of color (they can be
grayscale, or CMYK for print, or
RGB for web)

17. JPEG (also known as JPG), file types
ending in .jpg
• stands for Joint Photographic Experts
Group
• JPEG files are images that have been
compressed to store a lot of
information in a small-size file.
• Usually used for photographs on the
web, because they create a small file
that is easily loaded on a web page
and also looks good.
• It is bad for line drawings or logos or
graphics, as the compression makes
them look “bitmappy” (jagged lines
instead of straight ones).

18. What about GIFs?
• Stands for Graphic
Interchange Format
• compresses images but, as
different from JPEG, the
compression is lossless
• This format is never used for
photography, because of the
limited number of colors.
• GIFs can also be used for
animations

19. PNG, file types ending in .png
• stands for Portable Network
Graphics.
• It’s used almost exclusively for web
images, never for print images.
• It also allows for a full range of color
and better compression.
• PNG can retain it’s transparency

20. Psd, file types ending in .psd
• Photoshop document
• These types of files are very
large files allowing for large
colour information.
• Usually images are retained
in this format for print.
• These types of files are
generally raster files, but
there are some elements
which are vector based.

21. .Ai file types
• Illustrator document
• Vector images
• Use large colour
information

22. Bitmap
graphics
Vector graphics
What are they made up
of?
Pixels of different
colours
Objects
What can be edited? Individual pixels Individual objects
What is the file size? Large, as the
computer stores
details of every pixel
Small, as the computer stores
details of objects, which do not
require much memory
What happens when
they are resized?
They lose quality They do not lose quality
How real do they look? Real Not real (many of them look
like cartoon images)
Native formats .bmp .svg
Common file formats .bmp, .dib, jpeg, gif,
tiff, .png .psd
.cgm, .svg, .odg, .eps, .xml .ai