Adobe Photoshop CS4 - Manual (Page 521)

514 USING PHOTOSHOP CS4
Web graphics
Last updated 1/10/2010
Navigate in the dialog box
If the entire artwork is not visible in the Save For Web & Devices dialog box, you can use the Hand tool to bring another
area into view. Use the Zoom tool to magnify or reduce the view.
• Select the Hand tool (or hold down the spacebar), and drag in the view area to pan over the image.
• Select the Zoom tool , and click in a view to zoom in; hold down Alt (Windows) or Option (Mac OS), and click
in a view to zoom out.
You can also type a magnification percentage or choose one at the bottom of the dialog box.
View optimized image information and download time
The annotation area below each image in the Save For Web & Devices dialog box provides optimization information.
The annotation for the original image shows the file name and file size. The annotation for the optimized image shows
the current optimization options, the size of the optimized file, and the estimated download time using the selected
modem speed. You can choose a modem speed in the Preview pop-up menu.
Preview image gamma at different values
The gamma value of a computer monitor affects how light or dark an image looks in a web browser. Windows systems
use a gamma of 2.2, so images look darker on Windows than on Mac
OS systems, which are normally set to a gamma
of 1.8. In Photoshop, you can preview how your images will look on systems with different gamma values and make
gamma adjustments to the image to compensate. Activating a preview option does not affect final image output.
❖ Choose one of the following options by using the Save for Web/ & Devices dialog box Preview pop-up menu
Monitor Color Makes no adjustments to image gamma. Monitor Color is the default setting.
Macintosh (No Color Management) Displays an adjustment based on the default Macintosh gamma.
Windows (No Color Management) Displays an adjustment based on the default Windows gamma.
Use Document Profile Adjusts the gamma to match any attached document color profile in a color-managed
document.
Optimize an image for the web
1 Choose File > Save For Web & Devices.
2 Click a tab at the top of the dialog box to select a display option: Optimized, 2-Up, or 4-Up. If you select 4-Up, click
the preview you want to optimize.
3 (Optional) If your image contains multiple slices, select one or more slices you want to optimize.
4 Select a preset optimization setting from the Preset menu, or set individual optimization options. The available
options change depending on the file format you select.
If you’re working in 4-Up mode, choose Repopulate Views from the Optimize menu to automatically generate lower-
quality versions of the image after you change the optimization settings.
5 Fine-tune the optimization settings until you are satisfied with the balance of image quality and file size. If your
image contains multiple slices, be sure to optimize all the slices.
To restore an optimized preview to the original version, select it and then choose Original from the Preset menu.