Adobe Photoshop CS6, User Manual

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General options for Adobe PDF
You can set the following options in the General section of the Adobe PDF Options dialog box:
Description Displays the description from the selected preset, and provides a place for you to edit the description. You can paste a description
from the clipboard. If you edit the description of a preset, the word “(Modified)” is added at the end of the preset name.
Preserve Photoshop Editing Capabilities Preserves Photoshop data in the PDF, such as layers, alpha channels, and spot colors. Photoshop
PDF documents with this option can be opened only in Photoshop CS2 and later.
Embed Page Thumbnails Creates a thumbnail image of artwork.
Optimize For Fast Web View Optimizes the PDF file for faster viewing in a web browser.
View PDF After Saving Opens the newly created PDF file in the default PDF viewing application.
Compression and downsampling options for Adobe PDF
When saving artwork in Adobe PDF, you can compress text and line art, and compress and downsample bitmap images. Depending on the
settings you choose, compression and downsampling can significantly reduce the size of a PDF file with little or no loss of detail and precision.
The Compression area of the Adobe PDF Options dialog box is divided into three sections. Each section provides the following options for
compressing and resampling images in your artwork.
Downsampling If you plan to use the PDF file on the web, use downsampling to allow for higher compression. If you plan to print the PDF file at
high resolution, do not use downsampling. Select the Do Not Downsample option to disable all downsampling options.
Downsampling refers to decreasing the number of pixels in an image. To downsample images, choose an interpolation method—average
downsampling, subsampling, or bicubic downsampling—and enter the desired resolution (in pixels per inch). Then enter a resolution in the For
Images Above box. All images with resolution above this threshold are downsampled.
The interpolation method you choose determines how pixels are deleted:
Average Downsampling To Averages the pixels in a sample area and replaces the entire area with the average pixel color at the
specified resolution. Average downsampling is the same as Bilinear resampling.
Subsampling To Chooses a pixel in the center of the sample area and replaces the entire area with that pixel color. Subsampling
significantly reduces the conversion time compared with downsampling but results in images that are less smooth and continuous.
Subsampling is the same as Nearest Neighbor resampling.
Bicubic Downsampling To Uses a weighted average to determine pixel color, which usually yields better results than the simple
averaging method of downsampling. Bicubic is the slowest but most precise method, resulting in the smoothest gradations.
Compression Determines the type of compression that is used.
ZIP compression Works well on images with large areas of single colors or repeating patterns, and for black-and-white images that
contain repeating patterns. ZIP compression is lossless.
JPEG compression Is suitable for grayscale or color images. JPEG compression is lossy, which means that it removes image data and
may reduce image quality; however, it attempts to reduce file size with a minimal loss of information. Because JPEG compression
eliminates data, it can achieve much smaller file sizes than ZIP compression.
JPEG2000 Is the new international standard for the compression and packaging of image data. Like JPEG compression, JPEG2000
compression is suitable for grayscale or color images. It also provides additional advantages, such as progressive display and lossless
compression not available with JPEG. JPEG2000 is only available if Acrobat 6 (PDF 1.5) or later is selected from the Compatibility menu.
Image Quality Determines the amount of compression that is applied. The available options depend on the compression method. For JPEG2000
compression, Photoshop provides Lossless, Maximum, High, Medium, Low, and Minimum options. For JPEG compression, Photoshop provides
Minimum, Low, Medium, High, and Maximum options. For ZIP compression, Photoshop provides an 8
- bit Image Quality option. The 8 - bit Image
Quality option is lossless; that is, data is not removed to reduce file size, so image quality is not affected.
Tile Size Specifies the size of the tiles used in images with JPEG 2000 compression. When low Image Quality values are used to optimize images
smaller than 1024 x 1024 pixels, using the largest tile size produces better results. In general, a tile size of 1024 is best for most images. Lower
tile sizes are generally used for images with small dimensions (for viewing on devices such as mobile phones).
Convert 16 Bit/Channel Image To 8 Bit/Channel Converts 16 - bits-per-channel images to 8 - bits-per-channel images (selected by default). ZIP is
the only compression method available if the Convert 16 Bits option is unselected. If your document’s Compatibility setting is Acrobat 5 (PDF 1.4)
or earlier, the Convert 16 Bits option is unavailable, and images are automatically converted to 8 bits per channel.
Color management and PDF/X options for Adobe PDF
You can set the following options in the Output section of the Adobe PDF Options dialog box. Interactions between Output options change
depending on whether Color Management is on or off and which PDF standard is selected.
Color Conversion Specifies how to represent color information in the Adobe PDF file. When you convert color objects to RGB or CMYK, also
select a destination profile from the pop-up menu. All spot color information is preserved during color conversion; only the process color
equivalents convert to the designated color space.
No Conversion Preserves color data as is.
Convert To Destination Converts all colors to the profile selected for Destination. Whether the profile is included or not is determined by
the Profile Inclusion Policy.