Adobe 23101335 User Guide - Page 353

Previewing browser dither, Photoshop Choose Browser Dither from

Page 353 highlights

ADOBE PHOTOSHOP 6.0 343 User Guide The Dither percentage controls the amount of dithering that is applied to the image. A higher dithering percentage creates the appearance of more colors and more detail in an image, but can also increase the file size. For optimal compression, use the lowest percentage of application dither that provides the color detail you require. You can use an alpha channel to vary the Dither percentage across an image. This technique produces higher-quality results in critical image areas without sacrificing file size. (See "Using channels to modify dithering" on page 329.) Previewing browser dither You can preview browser dither directly in Photoshop or ImageReady, or in a browser that uses an 8-bit color display (256-color mode). To preview browser dither: With an optimized file displayed, preview dither in the respective application: • (Photoshop) Choose Browser Dither from the document panel menu in the Save for Web dialog box. (To view the menu, click on the triangle near the upper right corner of the document panel.) • (ImageReady) Choose View > Preview > Browser Dither. A check mark next to the command indicates that it is turned on. Choose View > Preview > Browser Dither again to turn the command off. To preview browser dither in a browser: 1 Set your computer's color display to 8-bit color (256 colors). See your computer operating system's documentation for information on changing the color display. 2 Do one of the following: • Launch your browser and open an optimized image directly in the browser. • With an optimized image displayed, click the Preview in Browser button in the toolbox. Minimizing browser dither Using colors in the Web palette ensures that colors won't dither when displayed in browsers on either Windows or Macintosh operating systems capable of displaying at least 256 colors. You have several options for choosing Web-safe colors: • When creating an original image, you can use the color picker, Color palette, and Swatches palette to choose Web-safe colors. For more information, see "Using Web-safe colors" in online Help. • In optimized GIF and PNG-8 images, you can shift existing colors to Web-safe colors using the color table. (See "Shifting to Web-safe colors" on page 334.)

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343
ADOBE PHOTOSHOP 6.0
User Guide
The Dither percentage controls the amount of
dithering that is applied to the image. A higher
dithering percentage creates the appearance of
more colors and more detail in an image,
but can also increase the file size. For optimal
compression, use the lowest percentage of
application dither that provides the color detail
you require.
You can use an alpha channel to vary the
Dither percentage across an image. This
technique produces higher-quality results in critical
image areas without sacri
cing
le size. (See
Using
channels to modify dithering
on page 329.)
Previewing browser dither
You can preview browser dither directly in
Photoshop or ImageReady, or in a browser that
uses an 8-bit color display (256-color mode).
To preview browser dither:
With an optimized file displayed, preview dither in
the respective application:
(Photoshop) Choose Browser Dither from the
document panel menu in the Save for Web dialog
box. (To view the menu, click on the triangle near
the upper right corner of the document panel.)
(ImageReady) Choose View > Preview >
Browser Dither. A check mark next to the
command indicates that it is turned on. Choose
View > Preview > Browser Dither again to turn the
command off.
To preview browser dither in a browser:
1
Set your computer’s color display to 8-bit color
(256 colors). See your computer operating
system’s documentation for information on
changing the color display.
2
Do one of the following:
Launch your browser and open an optimized
image directly in the browser.
With an optimized image displayed, click the
Preview in Browser button in the toolbox.
Minimizing browser dither
Using colors in the Web palette ensures that colors
won’t dither when displayed in browsers on either
Windows or Macintosh operating systems capable
of displaying at least 256 colors.
You have several options for choosing Web-safe
colors:
When creating an original image, you can use
the color picker, Color palette, and Swatches
palette to choose Web-safe colors.
For more information, see “Using Web-safe
colors” in online Help.
In optimized GIF and PNG-8 images, you can
shift existing colors to Web-safe colors using the
color table. (See “Shifting to Web-safe colors” on
page 334.)