Adobe photoshop elements 用户手册
CHAPTER 2
52
Getting Images into Photoshop Elements
You must install the TWAIN device and its
software, and restart your computer, before you
can use it to import images into Photoshop
Elements. See the documentation provided by
your device manufacturer for installation
information.
software, and restart your computer, before you
can use it to import images into Photoshop
Elements. See the documentation provided by
your device manufacturer for installation
information.
To import an image using the TWAIN interface:
Do one of the following:
•
Choose File > Import, and choose the device you
want to use from the submenu.
•
Click Acquire on the Quick Start screen that
appears when you start Photoshop Elements.
Optimizing the dynamic range of the scan
Keep in mind that the human eye can detect a
wider tonal range than can be printed. If your
scanner allows, set the black and white points
before scanning a file to produce the best tonal
range and capture the widest dynamic range. Then
use Photoshop Elements’s color adjustment tools
to set the white and black points for the scanned
image. (See “Adjusting tonal range” on page 85.)
wider tonal range than can be printed. If your
scanner allows, set the black and white points
before scanning a file to produce the best tonal
range and capture the widest dynamic range. Then
use Photoshop Elements’s color adjustment tools
to set the white and black points for the scanned
image. (See “Adjusting tonal range” on page 85.)
Eliminating unwanted color casts
If your scanned image contains an unwanted color
cast, for example if the colors in the image are all
too red in color, you can perform a simple test to
determine whether the cast was introduced by
your scanner. If it was, you can use the same test
file to create a color-cast correction for all images
scanned with the scanner.
cast, for example if the colors in the image are all
too red in color, you can perform a simple test to
determine whether the cast was introduced by
your scanner. If it was, you can use the same test
file to create a color-cast correction for all images
scanned with the scanner.
To identify and correct a color cast introduced by
a scanner:
1
Make sure that your monitor has been
calibrated. (See “Calibrating your monitor” on
page 66.)
page 66.)
2
Open a new file, and use the linear gradient
tool (
) to create a blend from pure black to
pure white.
3
Choose Image > Adjustments > Posterize, and
posterize the blend using 11 levels.
4
Print the 11-step gray wedge on a black-and-
white printer, and then scan it into Photoshop
Elements.
Elements.
Note: You can also perform this test using an
18-percent neutral gray card or an 11-step gray
wedge from a photography store.
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.
and B values indicate a color cast.
6
Write down the R, G, and B values.
7
Open the scanned image you want to correct,
choose Enhance > Brightness/Contrast > Levels,
and enter the R, G, and B values you just recorded.
and enter the R, G, and B values you just recorded.
Importing images from a digital
camera
camera
Photoshop Elements works with digital camera
software to import images directly from a camera.
Make sure that the software and drivers that came
with your digital camera are properly installed
before you import images.
software to import images directly from a camera.
Make sure that the software and drivers that came
with your digital camera are properly installed
before you import images.