Adobe photoshop elements 사용자 설명서

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CHAPTER 2
48
Getting Images into Photoshop Elements
Printer resolution
The number of ink dots per 
inch (dpi) produced by all laser printers. Most 
desktop laser printers have a resolution of 600 dpi. 
Ink jet printers produce a spray of ink, not actual 
dots; however, most ink jet printers have an 
approximate resolution of 300 to 600 dpi and 
produce good results when printing images up 
to 150 ppi.
File size
The digital size of an image, measured in 
kilobytes (K), megabytes (MB), or gigabytes (GB). 
File size is proportional to the pixel dimensions of 
the image. Images with more pixels may produce 
more detail at a given printed size, but they require 
more disk space to store and may be slower to edit 
and print. For instance, a 1-by-1-inch, 200-ppi 
image contains four times as many pixels as a 
1-by-1-inch, 100-ppi image and so has four times 
the file size. Image resolution thus becomes a 
compromise between image quality (capturing all 
the data you need) and file size. 
Another factor that affects file size is file format—
due to varying compression methods used by GIF, 
JPEG, and PNG file formats, file sizes can vary 
considerably for the same pixel dimensions. 
Similarly, color bit-depth and the number of layers 
in an image affect file size. 
Photoshop Elements supports a maximum file size 
of 2 GB and maximum pixel dimensions of 30,000 
by 30,000 pixels per image. This restriction places 
limits on the print size and resolution available to 
an image.
Changing image size and 
resolution
Once you have scanned or imported an image, 
you may want to adjust its size. The Image Size 
command lets you adjust the pixel dimensions, 
print dimensions, and resolution of an image.
Keep in mind that bitmap and vector data can 
produce different results when you resize an 
image. Bitmap data is resolution-dependent; 
therefore, changing the pixel dimensions of a 
bitmap image can cause a loss in image quality and 
sharpness. In contrast, vector data is resolution-
independent; you can resize it without losing its 
crisp edges.
Displaying image size information
You can display information about the current 
image size using the information box at the 
bottom of the application window (Windows) 
or the document window (Mac OS). (See “Using 
the status bar” on page 30.)
To display the current image size:
Click the file information box, and hold down the 
mouse button. The box displays the width and 
height of the image (both in pixels and in the unit 
of measurement currently selected for the rulers), 
the number of channels, document dimensions, 
and the image resolution.