Raster images are composed of pixels in a grid structure, so increasing the size results in loss of quality, while vector images use mathematical equations to define shapes so can be resized without quality loss. Common image file formats include JPEG, GIF, and TIFF, with JPEG best for photos due to high compression, GIF for animations and solid colors, and TIFF for quality banners and posters. Vector images have advantages of easy scaling and manipulation without quality loss, while raster is best for complex photos.

1. Portfolio Task 5
Imaging Presentions
by Luke Kersey

2. Definitions
Digital Imaging: Images that can be stored on
a computer or digital device.
Raster Images: A dot matrix data structure
representing a generally rectangular grid of
pixels
Vector Images: A vector image is a computer
image that uses a Wire Frame or Outlines to
define a shapes area.

3. Raster Images
A raster image is a collection of dots called pixels.
Each pixel is a tiny square with assigned color value.
They are created using a grid of pixels to define the image.
When you attempt to increase the size of an image created in a raster based program, the pixels defining the image can be
increased in either number or size.
Increasing the number of pixels or making the pixels bigger in an image results in the original data being spread over a larger area.
Spreading the pixels over a larger area causes the image to begin to lose detail and clarity. When an image is scanned, the image is
converted to a collection of pixels called a raster image.
Scanned graphics and web graphics are the most common forms of raster images.

4. Vector Images
The word “vector” is a synonym for line.
They are composed of mathematically-defined geometric shapes—lines, objects and fills.
When creating a vector image in a vector illustration program, node or drawing points are inserted and lines and curves connect
notes together. This is the same principle as “connect the dots”.
Each node, line and curve is defined in the drawing by the graphics software by a mathematical description.
They usually are easily modified within the creating application and generally are not affected detrimentally by scaling (enlarging
or reducing their size).
If the image is increased in size, the equation is recalculated accordingly resulting in the image increasing in size with no loss of
data or detail.
A vector object will have a “wireframe” underneath the colors in the object. In a vector object, colors are like clothes over the top
of a skeleton.
They’re defined as solid objects, and can be moved around in full, or grouped together with other objects.

5. Advantages/Disadvantages
ADVANTAGES DISADVANTAGES
RASTER • Best for photographs • Can not keep quality
and complex images while resizing
VECTOR • Can be easily scaled • Cannot be used to
and manipulated store complex images
without quality loss like photos
• Easy to render • High resolution
• Vector files are useful screens are needed
for storing images to show the pictures
composed of line at the best quality
based elements

6. Image File Formats
Image file formats are standardized means of
organizing and storing digital images.
Some examples are:
.bmp
.gif
.jpg
.tiff
.png

7. JPEG, GIF and TIFF
ADVANTAGES DISADVANTAGES USED FOR
JPEG Works very well for Compression Used for high
photographs. drastically reduces quality photographic
image quality. images.
GIF Good for websites Limited colour Animations and
and can be depth. images with large
animated areas of solid colour
TIFF Very high quality No good for internet Big banners and
use because of posters such as real
large filesizes estate signs

8. References
http://brycetech.daz3d.com/tutor/windows/jp
eg_compression.html
http://en.wikipedia.org/wiki/Vector_graphics
http://designwashere.com/design-battle-
vector-vs-raster/