After you have created an image with a transparent color, you must save the image in either a GIF or PNG format to preserve the transparency.
Saving as a GIF
If you opt to save as a GIF, you’ll need to check the box marked Save As Transparent in the Save As dialog. If your image contains more than 256 colors, (also known as 8-bit color) FotoFinish will prompt you to reduce the number of colors.
Reducing the color depth to save as GIF
If you select Continue, FotoFinish will automatically convert the image to 8-bit color, choosing the optimal palette to preserve the appearance of your original image. (If your image is a photograph, it will probably lose some quality when rendered in 256 colors.)
If you select Convert, FotoFinish will present the Change Number of Colors dialog, which allows you to manually select your color palette and dithering patterns. (Recommended for advanced users only.) You can learn more about these options in Understanding Color chapter.
Saving as a PNG
If you opt to save as a PNG, you’ll need to check the box marked Save As Transparent in the Save As dialog. If your image consists of more than 256 colors, (also known as 8-bit color) FotoFinish will present you with the choice of saving as True Color or converting to Indexed Color.
Options for saving a PNG with transparency
Unlike the GIF format, PNG can support transparency in True Color mode. This means your image will not lose quality as it would when reduced to 256 colors. Unfortunately, True Color PNG images do not display properly in many web browsers. For web use, therefore, the safe option is to Convert to Indexed color.
Related topics:
File Formats and Image Properties