Optimization options for PNG-24 format

PNG-24 is suitable for compressing continuous-tone images; however, it produces much larger files than JPEG format. (See About PNG-24 format.)

The advantage of using PNG-24 is that it can preserve up to 256 levels of transparency in an image (whereas JPEG saves pixels as fully opaque). To save an image with multilevel transparency, select Transparency. For more information about the Interlaced, Transparency, and Matte options, see Optimization options for GIF and PNG-8 formats.

To optimize a file according to a specified file size:

1. In the Optimize panel of the Save For Web dialog box, select Optimize to File Size from the Optimize panel menu.
2. Specify a Start With option:
• Current Settings to use current optimization settings.
• Auto Select GIF/JPEG to automatically generate a GIF or JPEG. (GoLive analyzes the colors in the image and automatically selects GIF or JPEG format.)
3. Enter a value for file size.
4. Click OK.

Note: The file size displayed in the Save For Web dialog box may be larger than the size on your local hard disk because GoLive adds Smart Object optimization settings to the target file. You can remove this extra information at the time of upload by choosing Edit > Preferences, then expanding Site, clicking Upload/Synch Times, and selecting the "Strip GoLive data from media files" option. However, the target file will lose its Smart Object functionality. This procedure can also be done on site export (local) and site publish (Workgroup server). The user can also change the settings "on the fly" during the upload/export/publish process.