Exporting Images - Adobe PHOTOSHOP 5.0 User Manual

Saving files in JPEG format
When saving in Joint Photographic Experts Group
(JPEG) format, you can specify the image quality
and compression level. To specify image quality
and compression, enter a value between 0 and 10,
or choose an option for Quality, or drag the slider.
There's always a trade-off between image quality
and the amount of compression: higher-quality
images use less compression (and more disk space)
than lower-quality images.
You can also select a format option for the JPEG
file. Select Baseline ("Standard") to use a format
recognizable to most Web browsers. The Baseline
Optimized format optimizes the color quality of
the image and can produce a slightly smaller file
size, but is not supported by all Web browsers.
The Progressive format causes the image to display
gradually as it is downloaded—in a series of scans
(you specify how many) showing increasingly
detailed versions of the entire image. However,
progressive JPEG images files are slightly larger in
size, require more RAM for viewing, and are not
supported by all applications and Web browsers.
Because the JPEG format discards data, it is
important to save JPEG files only once. Edit and
save your image in a format that does not discard
data (such as the Photoshop format), and save in
JPEG format only as a final step.
For a color illustration of images saved as
JPEG, see page 235.
Note: Some applications may not be able to read a
CMYK file saved in JPEG format. In addition, if you
find that a Java application cannot read your JPEG
file (in any color mode), try saving the file without a
thumbnail preview.

Exporting images

Adobe Photoshop includes plug-in modules
for creating Graphics Interchange Format (GIF)
files for online display and exporting paths to
Adobe Illustrator (see "Exporting paths to Adobe
Illustrator" on page 328).
The GIF89a Export module lets you convert an
RGB or indexed-color image to GIF89a format
and assign background transparency to the image.
Background transparency lets you place a non-
rectangular foreground object on the colored
background of a Web page. You can also save
indexed-color images as GIF files using the File >
Save As command (see "About file formats" on
page 321).
For assistance with saving an image with
transparency, choose Help > Export Trans-
parent Image. This interactive wizard helps you
prepare images for export to the Web.
To use an export module:
Choose File > Export, and select an export format
or method from the submenu.
See the following sections for a discussion of the
GIF89a export module.
Exporting RGB images to GIF
When you export an RGB image to GIF format,
the export module creates a reduced color palette
for the image.
ADOBE PHOTOSHOP 5.0 317
User Guide