Adobe photoshop cs2 Benutzerhandbuch
ADOBE PHOTOSHOP CS2
User Guide
182
Screen frequency examples
A. 65 lpi: Coarse screen typically used to print newsletters and grocery coupons
A. 65 lpi: Coarse screen typically used to print newsletters and grocery coupons
B. 85 lpi: Average screen typically used to print
newspapers
C. 133 lpi: High-quality screen typically used to print four-color magazines
D. 177 lpi: Very fine screen typically used for an-
nual reports and images in art books
Changing image size and resolution
Adjusting image size and resolution
After you have scanned or imported an image, you may want to adjust its size. In Photoshop, you use the Image Size
dialog box to adjust the pixel dimensions, print dimensions, and resolution of an image; in ImageReady, you can
adjust only the pixel dimensions of an image.
dialog box to adjust the pixel dimensions, print dimensions, and resolution of an image; in ImageReady, you can
adjust only the pixel dimensions of an image.
For assistance with resizing and resampling images in Photoshop, choose Help > Resize Image. This interactive
wizard helps you scale your images for print or online media.
wizard helps you scale your images for print or online media.
Remember, 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 degrade image quality and
sharpness. In contrast, vector data is resolution-independent; you can resize it without losing its crisp edges.
resolution-dependent; therefore, changing the pixel dimensions of a bitmap image can degrade image quality and
sharpness. In contrast, vector data is resolution-independent; you can resize it without losing its crisp edges.
To display the current image size
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).
window (Windows) or the document window (Mac OS).
❖
Do one of the following:
•
(Photoshop) Press Alt (Windows) or Option (Mac OS), position the pointer over 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, and the image resolution.
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, and the image resolution.
•
(ImageReady) Click an image information box, and select Image Dimensions from the pop-up menu. The box
displays the width and height of the image, in pixels.
displays the width and height of the image, in pixels.
Resampling
Resampling refers to changing the pixel dimensions (and therefore display size) of an image. When you downsample
(decrease the number of pixels), information is deleted from the image. When you resample up (increase the number
of pixels, or upsample), new pixels are added. You specify an interpolation method to determine how pixels are added
or deleted.
(decrease the number of pixels), information is deleted from the image. When you resample up (increase the number
of pixels, or upsample), new pixels are added. You specify an interpolation method to determine how pixels are added
or deleted.
A
B
C
D