Files can be converted from one format to
another. Files can be “saved as” and the option
dropdown will give you several options.
Files can be exported and imported into various
The size of a bitmap graphic file saved to disk
depend upon the format of the file and the options
taken when saving it.
Vector files are usually a lot smaller and do not
have save options for controlling file size
because they are already as small as they will
Controlling the file size is achieved by setting the
compression or quality level when saving the
The same graphic file might have different sizes
using JPEG quality settings.
Graphic sizes with different
JPEG quality settings.
100% 90% 60% 40% 10%
440KB 216KB 116KB 92KB 41KB
Graphic sizes in different
BMP GIF JPG PNG TIF
2305KB 209KB 440KB 348KB 2305KB
File format is the way the graphic is internally
structured. Each file format uses a different
structure – a program using that format must be
able to understand the structure so it knows
how to show the graphic on the screen, print it,
edit it etc.
Compression techniques are used to reduce the
disk size of a file. Being able to make a file size
smaller is very important if file size is an issue
File size is important if the file is to be
transmitted to another location (a small file
File size is important is there is a small amount
of storage space ( the file needs to be reduced in
size to fit)
Re-cap on Vector /Bitmap
Vector graphics follow mathematical rules.
Shapes are understood by vector graphics
software as coordinate points joined by lines with
a defined fill.
A line joining points may be
straight or curved and has
properties such as thickness,
colour, solid/dashed. There
could be no fill, making the
shape transparent or it could
have more than one colour or
Bitmap or raster graphics are pixel orientated
meaning that the image is made from a lot of pixels
each a tiny dot in the image with a colour. In
specific software you can zoom in enough to edit
The mathematical way in which vector images are
stored and manipulated makes them easy to edit
and re-size and result in small file sizes.
Bitmap images allow editing that is much more
complex than that possible with vectors.
Re-sizing a bitmap needs software to analyse the
pixels in the image, then recreate a new set of
pixels to make the image a new size.
The will be loss of quality and there will always
be a limit to how large a bitmap can be
As the colour information of every pixel needs to
be stored in a bitmap image the file size can end
File Size Small Large files sizes,
pictures with large
Scaling Very scalable to Pixilation occurs
any size without
loss of quality
How created User created with Scanner or digital
mouse of graphics camera
Typical uses Diagrams Photographs