beautypg.com

Resampling – Adobe Photoshop CS3 User Manual

Page 71

background image

PHOTOSHOP CS3

User Guide

64

Screen frequency examples
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 annual reports and
images in art books

Resampling

Resampling is changing the amount of image data as you change either the pixel dimensions or the resolution 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.

Resampling pixels
A. Downsampled B. Original C. Resampled up (selected pixels displayed for each set of images)

Keep in mind that resampling can result in poorer image quality. For example, when you resample an image to larger
pixel dimensions, the image loses some detail and sharpness. Applying the Unsharp Mask filter to a resampled image
can help refocus the image details.

A

B

C

D

A

B

C