This is the tutorial for optimising still gifs
in adobe photoshop. These other tutorials are also available:
In many ways still gifs are the easiest files to optimise. As long
as a gif file type is appropriate and the image is a sensible size
it is rare for a gif file to be large. Never the less here is how
i go about reducing their file size.
Step 1 - Image size
This is all about common sense. Just think to yourself
"will the board really want to see an 800x600 paintmash of
my dog" and the chances are the probably won't. 280px wide
is the reccomended width and as a rule i find it best to stick to
this but by all means go a little over if you think it's nessecary.
Step 2 - Export optimisation
To export a still gif you first need to go to file
/ save for web:
This will bring up the image optimisation
window, here you will find the gif export optimisation settings:
The most important tools for us here
are the palette options, dither and the lossy tool. The fastest
way to reduce the image size is to reduce the number of colours.
Images typicaly still look perfectly acceptable with 64 or less
colours. To help with this we use the palette selector:
The perceptual, adaptive and selective
palettes will all pick the colours which best approximate the orignal
image for a given palette size. They each do this using a different
algorithm so by experimentation you can often improve the look and
file size of your image.
Lossy averages out the pixels in your
image and thus can reduce file sizes dramatically but at the expense
of heavily reduced image quality. I rarely use a lossy of more than
Dither is the gif format's way of approximating
those colours which are not found in it's palette. I would usually
have this set to no dither as it increases file sizes dramtaically
and often means jpeg may have been a better choice of file format.
Sometimes however a little dither can improve the look of an image
without too substantial a cost in terms of file size this is up
to you to decide.
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.