Adobe 23101335 User Guide - Page 335

Setting optimization options for PNG-24, format, Optimizing by file size

Page 335 highlights

ADOBE PHOTOSHOP 6.0 325 User Guide Setting optimization options for PNG-24 format PNG-24 format is suitable for compressing continuous-tone images. However, PNG-24 files are often much larger than JPEG files of the same image. PNG-24 format is recommended only when working with a continuous-tone image that includes multilevel transparency. (See "About PNG-24 format" on page 320.) To optimize an image in PNG-24 format: 1 Select a view in which to apply the optimization setting. 2 Select the slice or slices to which you want to apply the optimization setting. (See "Selecting slices" on page 276.) 3 In the Optimize panel/palette, choose PNG-24 from the File Format menu in the Optimize panel/palette. 4 Select Interlaced to create an image that displays low-resolution versions in a browser while the full image file is downloading. Interlacing can make downloading time seem shorter, and assures viewers that downloading is in progress. 5 If the image contains transparency, choose an option for preserving or filling transparent pixels: • Select Transparency (the default setting) to preserve transparent pixels as transparent. • Deselect Transparency to fill transparent pixels with the Matte color. Optimizing by file size You can optimize an image or slice to an approximate file size. This feature enables you to quickly achieve a desired file size without having to test different optimization settings. To optimize a file according to a specified file size: 1 Select Optimize to File Size from the Optimize panel/palette menu. 2 Select a Start With option: • Current Settings to use current optimization settings. • Auto Select GIF/JPEG to automatically generate a GIF or JPEG. (Photoshop or ImageReady selects GIF or JPEG format, depending on an analysis of colors in the image.) 3 Select a Slices option: • Current Slice to optimize the selected slice to approximately the specified file size. • All Slices Separately to optimize each slice in the image to approximately the specified file size. • All Slices Together to optimize the sum of the size of all slices to approximately the specified file size. The total value is apportioned to individual slices based on each slice's relative size. For example, if you select three slices, one of which is twice as large as the other two, the large slice is optimized to 50% of the specified file size, and each of the other slices is optimized to 25% of the specified file size. 4 Specify a value for Desired File Size. 5 Click OK.

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325
ADOBE PHOTOSHOP 6.0
User Guide
Setting optimization options for PNG-24
format
PNG-24 format is suitable for compressing
continuous-tone images. However, PNG-24 files
are often much larger than JPEG files of the same
image. PNG-24 format is recommended only
when working with a continuous-tone image that
includes multilevel transparency. (See “About
PNG-24 format” on page 320.)
To optimize an image in PNG-24 format:
1
Select a view in which to apply the optimization
setting.
2
Select the slice or slices to which you want to
apply the optimization setting. (See “Selecting
slices” on page 276.)
3
In the Optimize panel/palette, choose PNG-24
from the File Format menu in the Optimize
panel/palette.
4
Select Interlaced to create an image that displays
low-resolution versions in a browser while the full
image file is downloading. Interlacing can make
downloading time seem shorter, and assures
viewers that downloading is in progress.
5
If the image contains transparency, choose an
option for preserving or filling transparent pixels:
Select Transparency (the default setting) to
preserve transparent pixels as transparent.
Deselect Transparency to fill transparent pixels
with the Matte color.
Optimizing by file size
You can optimize an image or slice to an approx-
imate file size. This feature enables you to quickly
achieve a desired file size without having to test
different optimization settings.
To optimize a file according to a specified file size:
1
Select Optimize to File Size from the Optimize
panel/palette menu.
2
Select a Start With option:
Current Settings to use current optimization
settings.
Auto Select GIF/JPEG to automatically generate
a GIF or JPEG. (Photoshop or ImageReady selects
GIF or JPEG format, depending on an analysis of
colors in the image.)
3
Select a Slices option:
Current Slice to optimize the selected slice to
approximately the specified file size.
All Slices Separately to optimize each slice in the
image to approximately the specified file size.
All Slices Together to optimize the sum of the
size of all slices to approximately the specified file
size. The total value is apportioned to individual
slices based on each slice’s relative size. For
example, if you select three slices, one of which is
twice as large as the other two, the large slice is
optimized to 50% of the specified file size, and
each of the other slices is optimized to 25% of the
specified file size.
4
Specify a value for Desired File Size.
5
Click OK.