User Guide

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ADOBE PHOTOSHOP ELEMENTS
User Guide
the optimized image. Use hard-edged trans-
parency when you don’t know the background
color of a Web page or when the Web page
background is a pattern. However, keep in mind
that hard-edged transparency can cause jagged
edges in the image.
GIF with hard-edged transparency, and displayed in
browser (inset at 300% magnification)
To create hard-edged transparency in a GIF or PNG-8:
1 Open or create an image that contains
transparency, and choose File > Save for Web.
2 In the Save For Web dialog box, select GIF or
PNG-8 as the optimization format.
3 Select Transparency.
4 Select None from the Matte pop-up menu to
make all pixels with greater than 50% trans-
parency fully transparent, and all pixels with 50%
or less transparency fully opaque.
Creating background matting in JPEG
images
When creating a JPEG from an original image that
contains layer transparency, you must matte the
image against a matte color. Since the JPEG format
does not support transparency, blending with a
matte color is the only way to create the
appearance of background transparency in a
JPEG. Fully transparent pixels are filled with the
matte color, and partially transparent pixels are
blended with the matte color. When the JPEG is
placed on a Web page with a background that
matches the matte color, the image appears to
blend with the Web page background.
To create a matted JPEG image:
1 Open or create an image that contains
transparency, and choose File > Save for Web.
2 In the Save For Web dialog box, select JPEG as
the optimization format.
3 Select a color from the Matte pop-up menu:
None, Eyedropper (to use the color in the
eyedropper sample box), White, Black, or Other
(to select a color using the color picker).
Note: When you select None, white is used as the
matte color.
Previewing and controlling
dithering
Most images viewed on the Web are created using
24-bit color displays (millions of colors mode),
but many Web browsers are used on computers
using only 8-bit color displays (256-color mode),
so that Web images often contain colors not
available to many Web browsers. Computers use a
technique called dithering to simulate colors not
available in the color display system. Dithering
creates adjacent pixels of different colors to give