If you are exporting an indexed-color image to GIF and want only the background to appear transparent, you may want to use an alpha channel to mask the background first. For example, certain elements in your image might have the same color as the background; if you define the background color as transparent, these elements will also appear transparent. By using a mask, you can apply transparency to just the background without affecting the elements that you want to remain visible.
Alternatively, you can convert the image to RGB mode, place the foreground selection on a new transparent layer, and hide the background before exporting the image to GIF. Converting the image to RGB lets you feather your selection and reduce the number of colors in an adaptive palette image when you convert the image to GIF.
To export an indexed-color image to GIF with a transparent background:
1.In the image, select the area that you want to remain visible.
2. Click the Save Selection button at the bottom of the Channels palette to create an alpha channel based on your selection. Note the name of the channel in the palette.
3.Choose File, Export, GIF89a Export.
4.For Transparency From, choose the alpha channel that you just created.
Then:
To invert what will be transparent in the image, hold down Option (Macintosh) or Alt (Windows) as you choose a channel for Transparency From in the GIF89a Export Options dialog box.
5.Choose additional export options as described in the previous procedure, to export an indexed-color image to GIF.
6.Click OK to export the file. Choose a location for the exported file, and click Save. The extension .gif is added automatically to the filename.
Good Luck!
*** Anne Palumbo is a consultant for business web designs. She is noted for her articles on marketing, design, and developer tricks and tips.
** As a web author, she designs original graphics, site layout configurations, provides database and script integration, and writes company content.
* You can find some of her work at: A.Palumbo Consultants
* You can also drop Anne a note - she’d be pleased to hear from you.
|
