Adobe photoshop cs2 사용자 설명서
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ADOBE PHOTOSHOP CS2
User Guide
To specify the halftone screen for Bitmap mode images
1
Choose Image > Mode > Bitmap.
2
Choose Halftone Screen from the Use menu; then click OK. The Halftone Screen dialog box opens.
3
For Frequency, enter a value for the screen frequency, and choose a unit of measurement. Values can range from
1 to 999 for lines per inch and from 0.400 to 400 for lines per centimeter. You can enter decimal values.
The screen frequency specifies the ruling of the halftone screen in lines per inch (lpi). The frequency depends on the
paper stock and type of press used for printing. Newspapers commonly use an 85-line screen. Magazines use higher
resolution screens, such as 133-lpi and 150-lpi. Check with your print shop for correct screen frequencies.
paper stock and type of press used for printing. Newspapers commonly use an 85-line screen. Magazines use higher
resolution screens, such as 133-lpi and 150-lpi. Check with your print shop for correct screen frequencies.
4
Enter a value for the screen angle in degrees from –180 to +180.
The screen angle refers to the orientation of the screen. Continuous-tone and black-and-white halftone screens
commonly use a 45˚ angle.
commonly use a 45˚ angle.
5
For Shape, choose the dot shape you want.
Original grayscale image, and Halftone Screen conversion: 53 lpi, 45˚ angle, round dot
You can save and reuse halftone screen settings by using the Save and Load buttons in the Halftone Screen dialog box.
Specifying custom halftone screens for Bitmap mode images
The Custom Pattern option in the Bitmap dialog box simulates the effect of printing a grayscale image through a
custom halftone screen. This method lets you apply a screen texture, such as a wood grain, to an image. To use this
option, you must first define a pattern.
custom halftone screen. This method lets you apply a screen texture, such as a wood grain, to an image. To use this
option, you must first define a pattern.
You can create a pattern representing the texture you want and then screen the grayscale image to apply the texture.
To cover the entire image, the pattern must be as large as the image. Otherwise, the pattern is tiled. For example, if
you apply a 1-inch-by-1-inch pattern to a 4-inch-by-4-inch image, the pattern appears as 16 squares. Photoshop
comes with several self-tiling patterns that can be used as halftone screen patterns.
To cover the entire image, the pattern must be as large as the image. Otherwise, the pattern is tiled. For example, if
you apply a 1-inch-by-1-inch pattern to a 4-inch-by-4-inch image, the pattern appears as 16 squares. Photoshop
comes with several self-tiling patterns that can be used as halftone screen patterns.
Because the Custom Pattern option simulates dark and light colors by making the halftone pattern thicker and
thinner, it makes sense to choose a pattern that lends itself to thickness variations, typically one with a variety of gray
shades.
thinner, it makes sense to choose a pattern that lends itself to thickness variations, typically one with a variety of gray
shades.
To prepare a black-and-white pattern for conversion, you can first convert the image to grayscale and then apply the
Blur More filter several times. This blurring technique creates thick lines tapering from dark gray to white.
Blur More filter several times. This blurring technique creates thick lines tapering from dark gray to white.
See also