Accurate image transparency in GIFs exported from Fireworks can be a challenge without some knowledge of the problems associated with transparent GIFs. This TechNote will explain transparency to allow FireworksÂsatisfactory transparency from a Fireworks exported GIF.
A GIF image gets its transparency from the color palette that is associated with it.ÂOne has to select the color or allow the application that generated the GIF to default to the color.
It is important that the user know what the HTML document's final background is, whether a hexidecimal color or an image file. This is essential to obtain correct transparency in GIF images that are to be placed in the document. Fireworks must have the same color or image on the background layer in order for the user to designate transparent indexed colors in the Export Preview window. When the user opens the Export Preview Window in Fireworks by choosing File > Export Preview, the Options tab allows the user to set transparency and to select, add and subtract colors from the palette so that the desired level of transparency can be achieved. The text at the top of the page shown is a transparent GIF. Notice that by turning off the colors in the palette, the anti-aliasing is lost. The anti-aliasing is exaggerated to emphasize that dithering and anti-aliasing colors can be problematic unless the background consists of a single color.
The following are tips for creating and exporting transparent GIFs: