Adobe Photoshop CS4 - Manual (Page 471)

464 USING PHOTOSHOP CS4
Saving and exporting images
Last updated 1/10/2010
Maximize compatibility when saving files
1 Choose Edit > Preferences > File Handling (Windows) or Photoshop > Preferences > File Handling (Mac OS).
2 Choose Always from the Maximize PSD and PSB File Compatibility menu. This saves a composite (flattened)
image along with the layers of your document.
Note: If file size is an issue or if you’re opening your files only in Photoshop, turning off Maximize PSD and PSB File
Compatibility reduces the file sizes significantly. From the Maximize PSD and PSB File Compatibility menu, choose
either Ask to be asked whether to maximize compatibility when you save or Never to save your document without
maximizing compatibility.
If you edit or save an image using an earlier version of Photoshop, unsupported features are discarded.
Photoshop format (PSD)
Photoshop format (PSD) is the default file format and the only format, besides the Large Document Format (PSB), that
supports all Photoshop features. Because of the tight integration between Adobe products, other Adobe applications,
such as Adobe Illustrator, Adobe InDesign, Adobe Premiere, Adobe After Effects, and Adobe GoLive, can directly
import PSD files and preserve many Photoshop features. For more information, see Help for the specific Adobe
applications.
When saving a PSD, you can set a preference to maximize file compatibility. This saves a composite version of a layered
image in the file so it can be read by other applications, including previous versions of Photoshop. It also maintains
the appearance of the document, just in case future versions of Photoshop change the behavior of some features.
Including the composite also makes the image much faster to load and use in applications other than Photoshop, and
may sometimes be required to make the image readable in other applications.
16-bits-per-channel and high dynamic range 32-bits-per-channel images can be saved as PSD files.
Photoshop 2.0 format
(Mac OS) You can use this format to open an image in Photoshop 2.0 or to export an image to an application
supporting only Photoshop 2.0 files. Saving in Photoshop 2.0 format flattens your image and discards layer
information.
Photoshop DCS 1.0 and 2.0 formats
Desktop Color Separations (DCS) format is a version of the standard EPS format that lets you save color separations
of CMYK images. You can use DCS 2.0 format to export images containing spot channels. To print DCS files, you must
use a PostScript printer.
Photoshop EPS format
Encapsulated PostScript (EPS) language file format can contain both vector and bitmap graphics and is supported by
virtually all graphics, illustration, and page-layout programs. EPS format is used to transfer PostScript artwork
between applications. When you open an EPS file containing vector graphics, Photoshop rasterizes the image,
converting the vector graphics to pixels.
EPS format supports Lab, CMYK, RGB, Indexed Color, Duotone, Grayscale, and Bitmap color modes, and does not
support alpha channels. EPS does support clipping paths. Desktop Color Separations (DCS) format, a version of the
standard EPS format, lets you save color separations of CMYK images. You use DCS 2.0 format to export images
containing spot channels. To print EPS files, you must use a PostScript printer.