| This is the tutorial for optimising animations
in abobe imageready. These other tutorials are also available:
Optimising gifs effectively can be difficult and may well result
in a loss of quality which you find hard to accept. There are three
strategies to deal with this:
- Spend an appropriate amount of time optimising and accept that
this is a compromise between quality and size.
- Spend an appropriate amount of time optimising the image and
post the compromise but also provide a link to the larger file
with a message warning of the size.
- Don't bother with the optimisation and just post a link, perhaps
using a still image from the animation to give a flavour of the
file.
It is important to remember that animated gifs are
not intended to produce epic masterpieces or wonderfully smooth
animation. 30fps animation is simply not an option and animations
longer than four or five seconds have to be carefully put together
to avoid an unacceptable file size.
Step 1 - Making the image.
These are a list of things to consider when making
your animation.
- Areas that stay static will not need to be reloaded in every
frame so if the animation only takes up a small portion of the
frame size (a waving hand or jumping kitten for example) then
try to keep the rest of the frame absolutely stationary.
- Areas of flat colour take up much less memory than areas of
blended colour so consider replacing the background with a flat
colour layer.
- The more frames your animation has the larger it will be. Remember
that to be funny an animation does not need to be smooth.
- Fades in gif animations require a huge amount of information
and should be avoided unless absolutely nessecary.
Step 2 - Resizing your image.
This is one of the key steps in reducing image size.
Remember, anything larger than 280px wide will be too large to be
frontpaged on b3ta and that plenty of images notably smaller than
this have been frontpaged in the past.
The way to reduce the size of an animation is with
the image size tool found in the image menu.

Try to reduce your image size as far
as possible without losing the meaning of your animation.
Step 3 - Export optimisation.
The final stage of the optimisation process
comes when you export the image. In imageready you control this
using the optimisation palette.

You already know the difference between
the file formats so i won't go into this again. The lossy tool averages
out pixels across your animation and is a quick way to reduce the
file size however this is often at the expense of an unacceptable
drop in image quality. I rarely use a lossy of more than 20-30 on
animations.
The palette tools are the most important
in terms of optimisation, often by reducing to 64 or even 32 colours
you can get a perfectly acceptable looking image for a vastly reduced
file size. The key to not losing is to choose an appropriate palette
type.

By using the selective, adaptive and
perceptual palette types the computer will automatically select
the colours that best approximate your image for a given number
of colours. They each do this using a different algorithm and so
by testing each of these you may find that some give better effects
than others.
Dither is what gifs use to approximate
colours which are not in their palettes. This requires a good deal
of information and thus can increase file sizes dramatically. I
would usually have very little dithering on my animations and often
none at all.
You can compare several different levels
of optimisation using the 2-up and 4-up options at the top of the
image window this will allow you to find the most suitable optimisation
for your animation.

Good luck with your optimisation, if
you have any further questions on the subject e-mail me and i'll
be more than happy to attempt to help you. |