| *note*
Software covered in these tutorials:
- Photoshop/imageready
- fireworks
- Paint shop pro/animation shop
- The GIMP
- Ulead Gif animator
If you have a request for additional software
you wish to see covered then e-mail me.
Image
optimisation (or optimization for the americans amongst you) is
one of the areas which newer b3ta members struggle with most. This
tutorial should prevent you from annoying those boarders who view
he site over dialup. Whilst the tutorial is designed with b3ta in
mind it also aims to provide you with skills useful in other we
work you may be doing.
Step 1 - How big should my files be?
For b3ta:
- Images need never be more than 50Kb
- Animations need never be more than 200Kb
But the general rule is that they should be as
small as possible.
Step 2 - Which file format should I use?
This is one of the most important steps in this
tutorial. The correct file format not only reduces the file size
of your image but choosing the wrong format can make your picture
look worse. There are two main file formats to choose from: .gif
and .jpg.
For an animated file your choice is simple. If
you wish to post to the board it should be an animated gif, else
you should consider making a flash file (.swf).
If you are making a still image then the choice
of format is a little more difficult and relies on understanding
a little about the way the compression algorithms in image formats
work. First of all allow me to give you some examples.
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|
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Chump.jpg - jpeg compression
medium quality ~9Kb
|
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Chumpcopy.gif - gif compression
128 colours full dither ~34Kb
|
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Medusa.gif
- gif compression 128 colours full dither ~7Kb |
|
Medusacopy.jpg
- jpeg compression medium quality ~39Kb |
As you can see from these examples picking the
wrong compression can lead to the file size being over double what
it need be.
The top image is produced from photographs and
images such as this will compress better as jpegs.
If you want more information about why this is the case then click
here.
The lower image was produced whilst doodling in
MS paint and images made up of flat colours such as this will compress
better as still gifs. This almost
invariable includes screenshots of anything other than computer
games.
One other important thing to note is that jpg
compression is especially poor for images containing text. The letters
lose their consistency and so become far less readable even at comparatively
high qualities. If text plays an important part in your image i
would strongly suggest using a gif file.
For more information about how
the formats work and why the above is the case Claws of doom put
together this
excellent guide.
Thanks to Spoon for his advice
and contributions to this section. |