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发信人: killest (victor), 信区: Graphics
标  题: PHOTOSHOP(23)-getting image into photoshop
发信站: 紫丁香 (Mon Mar 23 16:16:28 1998), 转信

Optimizing the dynamic range of the scan
When scanning an image, keep in mind that the
human eye can detect a wider tonal range than can
be printed. If your scanner lets you define the black
and white points, set the points before scanning
the file to produce the best tonal range and capture
the widest dynamic range. After opening the file in
Adobe Photoshop, use the color correction tools to
set the white and black points for the digitized
image. See Chapter 6, 揗aking Color and Tonal
Adjustments,� for more information about setting
the black and white points for an image.
Eliminating unwanted color casts
If your scanned image contains an unwanted color
cast, you can perform a simple test to determine
whether the cast has been introduced by your
scanner. If you find that it has, you can use the
same test file to create a color cast correction for all
images scanned using that scanner.
To identify and correct a color cast introduced by
a scanner:
1 Make sure that your monitor has been cali-brated
following the instructions starting on
page 85. This procedure will not work unless your
monitor has been calibrated.
2 Open a new Photoshop file and use the gradient
tool (G) to create a blend from pure black to pure
white.
3 Choose Image > Adjust > Posterize and
posterize the blend using 11 levels.
4 Print the 11-step gray wedge and then scan it
into Photoshop.
Note: You can also perform this test using an 18-
percent neutral gray card or an 11-step gray wedge
from a photography store.
5 Open the Info palette and read the RGB values
on-screen for each of the gray levels. Uneven R, G,
and B values indicate a color cast. See Chapter 4 for
more information on color and color values.
6 Use Levels or Curves to correct the color cast
(see Chapter 6 for instructions), and then save the
dialog box settings.
7 Open the scanned image you want to correct,
reopen the dialog box you used to correct the cast
in step 6, and load the saved settings.
Opening and importing images
Adobe Photoshop lets you open images in a variety
of file formats. You can have multiple image win-dows
open at one time.
Import choices appear in the file format list in the
Open dialog box or in the File > Import submenu.
If a file format does not appear, install the format抯
plug-in module, as explained on page 31.
Opening files
You can open files in the following ways: Double-clicking a file抯
icon on the desktop
(Windows 95, Windows NT) or a file抯 name in a
file list opens the file.
53 The Open command lets you open files saved in
formats that are supported by Photoshop (except
for those that use Import modules). On the
Macintosh, you can use the Open command to
open files in the format that you specify. In Windows, the Open
As command lets you
open a file that has a missing or incorrect file
extension, or a file that does not appear in the
Open dialog box. The Import command lets you open files saved
in formats that use plug-in import modules. You
can open anti-aliased PICT files and PICT
Resource files (Macintosh), Quick Edit versions of
Photoshop 2.0, Scitex � CT, uncompressed TIFF
files, and files scanned using the TWAIN interface.
You also use the Import command to use any
third-party import modules you抳e installed.
To open a file on the Macintosh:
1 Choose File > Open.
2 To display all files in the selected folder, select
Show All Files. To locate files in other folders, click
Find and type the filename.
3 To preview files before opening them (if a
preview has been saved with the image), select
Show Thumbnail. This option requires the Apple �
QuickTime extension. Files created with a version
of Adobe Photoshop prior to 2.5.1 must be resaved
for the preview to appear.
4 Select the file.
5 Click Open. In some cases, a dialog box appears,
letting you set the open options. The formats
requiring an open dialog box are discussed in the
following sections.
For more information on a specific file format, see
揂bout file formats� on page 318.
To open a file in Windows:
1 Choose File > Open.
2 For Files of Type, choose one of the following
options: All Formats to display all the files in the selected
directory. Any individual format to display only files saved
in that format.
3 Select the file.
4 Click Open. In some cases, a dialog box appears,
letting you set the open options. The formats
requiring an open dialog box are discussed in the
following sections.
For more information on a specific file format, see
揂bout file formats� on page 318.
To specify the file format in which to open a file:
Do one of the following: On the Macintosh, choose File > Open and
select Show All Files. For Format, choose the
desired file format and click Open. In Windows, choose File >
Open As. For Open
As, choose the desired format and click Open.
Note: If the file does not open, then the chosen
format may not match the file抯 true format, or the
file may be damaged.
CHAPTER 3 54
Getting Images into Photoshop
To use an import module:
Choose File > Import; then choose the import
module from the submenu.
The options for some import modules are dis-cussed
in the following sections.
Importing Adobe Illustrator files
You can import files created in Adobe Illustrator �
using the following methods: The File > Open command lets you open an
Adobe Illustrator file as a new Adobe Photoshop
image. The File > Place command places an Adobe
Illustrator file as a new layer into an existing
Photoshop image. The Edit > Paste commands lets you paste
copied Illustrator artwork into a Photoshop
image. You can choose to paste the artwork either
as pixels or as a path. For more information, see
揅opying between applications� on page 180.
When you open or place an Adobe Illustrator
image, Adobe Photoshop rasterizes the image. Ras-terizing
converts the mathematically defined lines
and curves of the vector image drawn in Adobe
Illustrator to the points (or pixels) displayed on a
grid in Adobe Photoshop. For more information,
see page 36.
To open an Adobe Illustrator image as a new Adobe
Photoshop image:
1 Choose File > Open.
2 Select the file you want to open, and click Open.
If the file does not appear, select Show All Files
(Macintosh) or, for Files of Type, choose All
Formats (Windows).
3 Indicate the desired dimensions, resolution,
and mode. To maintain the same height-to-width
ratio, select Constrain Proportions.
4 Select Anti-aliased to improve the quality of the
rasterized image.
5 Click OK.
To place artwork from Adobe Illustrator into an
Adobe Photoshop image:
1 Open the Adobe Photoshop image in which you
want to place the artwork.
2 Choose File > Place, and select the file you want
to place. Then click Open.
The placed artwork appears as a new layer inside a
bounding box at the center of the Adobe Photo-shop
image. The artwork maintains the aspect
ratio of the Adobe Illustrator file.
3 Use the following methods to adjust the placed
artwork: To move, position the pointer inside the
bounding box and drag.
55 To scale, drag one of the handles at the corners or
sides of the bounding box. Hold down Shift as you
drag a corner handle to constrain the proportions. To
rotate, position the pointer outside the
bounding box (the pointer turns into a curved
arrow) and drag.
4 To confirm the placement of the artwork, press
Return (Macintosh) or Enter (Windows). To
cancel the placement, press Esc.
Turning off anti-aliasing for imported
objects
The Anti-alias PostScript � option removes jagged
edges from a pasted or placed selection by making
a subtle transition between the edges of the selec-tion
and its surrounding pixels. When placing line
art, you can turn off the Anti-alias PostScript
option to help maintain the line art抯 hard edges as
it is rasterized.
To turn off the Anti-alias Postscript option:
1 Choose File > Preferences > General.
2 Deselect Anti-alias PostScript. Clearing this
option can decrease the time it takes to import
the file.
Opening PhotoCD files
To open PhotoCD files in Adobe Photoshop,
choose the Kodak � PhotoCD � format in the Open
dialog box. The PhotoCD plug-in module can
open 4096-by-6144-pixel resolution (64Base, 72
MB) images from Kodak Pro PhotoCD disks.
Note: The Kodak Precision Color Management
System (KPCMS), required to use the Kodak CMS
PhotoCD format, is automatically installed in your
System Folder when you install Adobe Photoshop.
You cannot save files in the PhotoCD format from
Adobe Photoshop.
The Kodak KCMS PhotoCD plug-in module lets
you read Photo YCC data from the disk and con-vert
it to either an Adobe Photoshop RGB or a Lab
color space. You can transform both the source
image and the destination image using the profiles
(or PT) you have installed. Using the Precision
CMS application lets you deliver the highest-qual-ity
image to Adobe Photoshop.
To open a Photo CD file:
1 Choose File > Open.
2 Select the Kodak CMS PhotoCD.
3 Select the file, and click Open.
4 Choose a resolution.
5 Deselect Landscape to open a portrait in its
original orientation. (When this option is selected,
portrait images are opened in Landscape orienta-tion.)
6 Click Source.
The first time you open a PhotoCD file, it opens
using the default Source and Destination profiles.
After you choose the profiles, they remain selected
until you change them.
7 Choose a device and a description from the list,
and then click OK.
8 Click Destination, and for Device, choose RGB
or Lab; then click OK.

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