Comparing optimized GIF, JPEG, and PNG formats

You can customize any of the optimized views in the Save For Web dialog box. To do this, you select one of the optimized image previews, and then select settings for it on the right side of the dialog box. By experimenting with different combinations of settings, you can get a good idea of which settings will best suit your purpose.

Before you begin, make sure that the optimized preview at the upper right is selected.

1 In the Settings pop-up menu on the right side of the Save For Web dialog box, select GIF 128 Dithered (if it is not already selected).

The information listed below the selected image preview changes.


Settings,(jaM28 Dithere^i; "J-(V)-

|GIF Lossy

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| Selective Colors


(Diffusion Dither

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Transparency Matte


|No Transparent"^] Amount


r Interlaced Web Snap

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Notice the dark group of pixels around the text and on the parrot's beak. (You may need to hold down Shift and drag the image again to see the beak.)

You'll use the two bottom versions of the image to compare GIF 128 Dithered optimization with JPEG and PNG optimization.

2 Click the lower-left version of the image to select it, and select the following JPEG options, one at a time, on the Settings pop-up menu:

• JPEG Low. Notice that the image details and text are unacceptably choppy.

• JPEG High.The image quality improves, but the file size increases significantly.

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