The first page of the PNG Wizard opens when you click the Use Wizard button at the bottom left corner of the dialog.
To open the PNG Wizard:
choose File > Export > PNG Optimizer to open the PNG Optimizer dialog, and then click the Use Wizard button.
PNG Wizard Page 1:
Select the image type: Palette-Based (256 colors or less), Greyscale (8-bit), or 16 million color (24-bit). Click the Next button to proceed to page 2.
PNG Wizard Page 2:
Choose the color that you want to make transparent. The color box displays the current background color. If the Wizard does not detect transparent information in the image, the page displays the following two options:
No transparency, which you choose to create a PNG file that does not contain a transparency, and
Convert matching colors to transparent, which you choose to create a PNG file containing a transparency.
To choose a color from the image, position the cursor over the color box, press and hold the Ctrl key, move the cursor over the image, and click the color. You can click inside the color box to open the Color dialog (24-bit images) or Image palette (8-bit images).
If the Wizard detects a transparency in the image, it displays a third option. This option, which is for retaining the existing transparency in the final image, is chosen by default. To use a different transparent color, choose the second option and select the new color. Click the Next button to proceed to page 3.
PNG Wizard Page 3:
Enter the background color of the Web page on which you will be using the image. The color box displays the current background color. To choose a color from the image, move the cursor over the image, and click the color. You can also click inside the color box to open the Color dialog (24-bit images) or Image palette (8-bit images), or right-click it to open the Recent Colors dialog.
PNG Wizard Page 4:
This page contains Image palette options. Use the default Web-safe palette option to create an image that looks the best with most browsers. If you choose to use the other palette, some image colors may not display correctly when downloaded. Click the Next button to proceed to page 5.
PNG Wizard Page 5:
Use the slider on this page to set the file size. As you drag the slider up, you increase the size by adding colors, which creates a better-looking image. As you drag the slider down, you remove colors, decrease the file size, and lower the image quality. Click the Next button to proceed to page 6, where you can view the image.
PNG Wizard Page 6:
The final page displays the result of your settings. To change a setting, click the Back button to return to the previous pages. Click the Finish button to close the Wizard and open the Save As dialog, where you type a name and select a location for saving the PNG file. The original image is not altered.