Adobe 13101332 - Photoshop - Mac User Manual page 457

Adobe Photoshop Help
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Generic PDF files Are created using applications other than Photoshop, such as Adobe
Acrobat and Adobe Illustrator, and can contain multiple pages and images. When you
open a Generic PDF file, Photoshop rasterizes the image.
PICT File
PICT format is widely used among Mac OS graphics and page-layout applications as an
intermediary file format for transferring images between applications. PICT format
supports RGB images with a single alpha channel, and indexed-color, grayscale, and
Bitmap-mode images without alpha channels. PICT format is especially effective at
compressing images with large areas of solid color. This compression can be dramatic for
alpha channels with their large areas of white and black.
When saving an RGB image in PICT format, you can choose either a 16-bit or 32-bit pixel
resolution. For a grayscale image, you can choose from 2, 4, or 8 bits per pixel. In Mac OS
with QuickTime installed, four JPEG compression options are available.
Note: In ImageReady, PICT format is supported in Mac OS only.
PICT Resource
(Mac OS) A PICT resource is a PICT file contained in a Mac OS file's resource fork—for
example, an application's splash screen or the contents of the Scrapbook. PICT Resource
format supports RGB images with a single alpha channel, and indexed-color, grayscale,
and Bitmap-mode images without alpha channels.
You can use the Import command or the Open command to open a PICT resource. When
saving a file as a PICT resource, you can specify the resource ID and resource name. As with
other PICT files, you also specify bit depth and compression options.
Pixar
The Pixar format is designed specifically for high-end graphics applications, such as those
used for rendering three-dimensional images and animation. Pixar format supports RGB
and grayscale images with a single alpha channel.
PNG
Developed as a patent-free alternative to GIF, Portable Network Graphics (PNG) format is
used for lossless compression and for display of images on the World Wide Web. Unlike GIF,
PNG supports 24-bit images and produces background transparency without jagged
edges; however, some Web browsers do not support PNG images. PNG format supports
RGB, indexed-color, grayscale, and Bitmap-mode images without alpha channels. PNG
preserves transparency in grayscale and RGB images.
QuickTime Movie (ImageReady)
QuickTime Movie format is a cross-platform format used for time-based data, such as
video and audio. In ImageReady, you can save animations as QuickTime movies and open
existing QuickTime movies as animations in order to optimize them for the Web.
Note: In Windows, QuickTime Movie format is visible in the Files of Type pop-up menu only
when QuickTime is installed on your computer.
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Saving and Exporting Images
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