Adobe Photoshop CC 2014 v.14.xx - Manual (Page 845)

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RLE (Run Length Encoding)
LZW (Lemple-Zif-Welch)
JPEG (Joint Photographic Experts Group)
CCITT
ZIP
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Note:
Always
Ask
Never
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About file compression
Many file formats use compression to reduce the file size of bitmap images. Lossless techniques compress the file without removing image detail
or color information; lossy techniques remove detail. The following are commonly used compression techniques:
Lossless compression; supported by some common Windows file formats.
Lossless compression; supported by TIFF, PDF, GIF, and PostScript language file formats. Most useful for images with
large areas of single color.
Lossy compression; supported by JPEG, TIFF, PDF, and PostScript language file formats.
Recommended for continuous-tone images, such as photographs. JPEG uses lossy compression. To specify image quality, choose an option from
the Quality menu, drag the Quality pop-up slider, or enter a value between 0 and 12 in the Quality text box. For the best printed results, choose
maximum-quality compression. JPEG files can be printed only on Level 2 (or later) PostScript printers and may not separate into individual plates.
A family of lossless compression techniques for black-and-white images, supported by the PDF and PostScript language file formats.
(CCITT is an abbreviation for the French spelling of International Telegraph and Telekeyed Consultive Committee.)
Lossless compression; supported by PDF and TIFF file formats. Like LZW, ZIP compression is most effective for images that contain large
areas of single color.
Maximize compatibility for PSD and PSB files
If you work with PSD and PSB files in older versions of Photoshop or applications that don’t support layers, you can add a flattened version of the
image to the saved file.
If you save an image in an earlier version of Photoshop, features that version doesn’t support are discarded.
1. Choose Edit > Preferences > File Handling (Windows) or Photoshop > Preferences > File Handling (Mac OS).
2. From the Maximize PSD and PSB File Compatibility menu, choose any of the following:
Saves a composite (flattened) image along with the layers of your document.
Asks whether to maximize compatibility when you save.
Saves only a layered image.
Choose Ask or Never if you want to significantly reduce file size.
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
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