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There are three basic
file formats that you encounter when using Fireworks to create and optimize
web graphics. Optimizing is the process of converting and compressing
images so that they download faster over the net. Here is a summary of
those files and their properties followed by step-by-step directions.
PNG-Portable
Network Graphic
This is the native, or default, file format for Fireworks. Use this format
to save original artwork produced in Fireworks to maintain the ability
to edit your images at a later date. Eventually you will be able to publish
images on the web in this format. It produces small files for both graphic
(solid-tone) and photographic (continuous-tone) images. Lossless format.
Supports transparency more complex than GIF format. Not yet supported
by Netscape or Internet Explorer. Do not publish images in PNG format!
JPG-Joint Photographic
Experts Group Excellent for compressing photographic images or graphics
with continuous-tones. Also works well with glows, gradients, soft shadow
effects, etc. Can contain 16.7 million colors (called 24-bit). Lossy format.
Because JPG is a lossy format don’t JPG a JPG as this can cause some
serious image degradation.
GIF-Graphic
Interchange Format
Works best with images that have large areas of solid colors. This would
include logos, cartoons, line art, illustrations, etc. Contains up to
256 colors (called 8-bit). Supports transparency and animation. Lossless
and lossy options.
All three of these
formats are cross-platform. This means they can be viewed on any type
of computer. Keep in mind that if you are working on PC your images will
appear brighter on a Mac. If you work on a Mac your images will appear
darker on a PC. Such is the web!
Step-by-step
When you have an image ready to optimize in Fireworks select the 2-up
tab over the image. This will show you two versions of your image. On
the left you will see your original, on the right, your optimized verision.
Open your Optimize window if it is not visible by going to Windows
on the main menu and selecting optimize. If you are working with a photograph
or an image with subtle tonal gradients use the jpg format. If your image
is made of mostly solid tones use the gif format. Choose the variables
which yield the highest image quality with the smallest file size. Some
example settings; for jpg use a quality setting below 95, turn off sharpen
jpeg edges, select remove unused colors. For gif use web adaptive, select
remove unused colors.
When you are ready
to export go to File>Export. Name your file, add the appropriate three
letter extension, either .jpg or .gif, and export the graphic to the appropriate
folder. When you close the original image in Fireworks it will ask you
if you want to save the changes. Choosing Yes will save the export settings
you just selected.
For more information
visit the Macromedia Fireworks
Support Center.
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