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ADOBE PHOTOSHOP CS2
User Guide
PNG-24
PNG-24 is suitable for compressing continuous-tone images; however, it produces much larger files than JPEG
format. The advantage of using PNG-24 is that it can preserve up to 256 levels of transparency in an image.
SWF
The Macromedia® Flash™ (SWF) file format is a vector-based graphics file format for the creation of scalable, compact
graphics for the web. Because the file format is vector-based, the artwork maintains its image quality at any
resolution. The SWF format is ideal for the creation of animation frames, but you can also save raster images in SWF
format or mix raster and vector graphics. See “Saving files in SWF format (ImageReady)” on page 671.
WBMP
WBMP format is the standard format for optimizing images for mobile devices, such as cell phones. WBMP supports
1-bit color, which means that WBMP images contain only black and white pixels.
See also
“Using the Save For Web dialog box” on page 625
“To optimize an image for the web” on page 628
Optimization options for JPEG format
C
A
B
Optimization settings for JPEG
A.
File Format menu
B.
Compression Quality menu
C.
Optimize menu
Quality
Determines the level of compression. The higher the Quality setting, the more detail the compression
algorithm preserves. However, using a high Quality setting results in a larger file size than using a low Quality setting.
View the optimized image at several quality settings to determine the best balance of quality and file size.
Optimized
Creates an enhanced JPEG with a slightly smaller file size. The Optimized JPEG format is recommended
for maximum file compression; however, some older browsers do not support this feature.
Progressive
Displays the image progressively in a web browser. The image appears as a series of overlays, enabling
viewers to see a low-resolution version of the image before it downloads completely. The Progressive option requires
use of the Optimized JPEG format.
Note:
Progressive JPEGs require more RAM for viewing and are not supported by some browsers.
Blur
Specifies the amount of blur to apply to the image. This option applies an effect identical to that of the Gaussian
Blur filter and allows the file to be compressed more, resulting in a smaller file size. A setting of 0.1 to 0.5 is recom
mended.
ICC Profile
Preserves the ICC profile of the artwork with the file. Some browsers use ICC profiles for color
correction. This option is available only after you saved an image with an ICC profile—it is not available for unsaved
images.
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