Adobe Photoshop CS5 for Photographers - Martin Evening [309]
The Image Size options are fairly similar to those found in the Image Image Size dialog box. Simply enter the new percentage with which to scale the image and check what impact this has on the file size (this changes the file size in all the optimized windows). An alternative approach is to select ‘Optimize To File Size’ from the fly-out menu (see Figure 14.10). You can use this to get the optimized file to match a specific kilobyte file size. If you wish, you can have Photoshop automatically determine whether it is better to save as a GIF or JPEG.
Figure 14.10 If you mouse down on the Options and settings menu (circled in red in Figure 14.8) you can choose ‘Optimize to File Size’, which opens the dialog shown here, where you can set a desired file size to optimize an image to.
Figure 14.8 The Save for Web interface.
Save options
The Save for Web dialog lets you save your output using: ‘Images only’, ‘HTML only’ or ‘HTML and Images’ (Figure 14.11). If you select ‘Images Only’, this simply saves a Web-ready image that you can use to place in a website design such as a blog entry, or as an image ready to email. If you select the ‘HTML and Images’ option, you can generate an HTML file with a link to the image, which will be placed in an accompanying ‘images’ folder.
Figure 14.11 The Save for Web & Devices save options.
Edit Output Settings
The ‘Edit Output Settings’ option (in the Options and settings menu) lets you determine the various characteristics of the Save for Web output files such as: the default naming structure of the image files and slices; the HTML coding layout; and whether you wish to save a background file to an HTML page output.
Efficient JPEG saving
The Save for Web & Devices dialog may look intimidating, but once you figure out which settings need concern you, simply save these as a custom setting. I have also recorded the Save for Web & Devices as an action step, so that I don't even need to look at this dialog. The main thing to be aware of here is that Save for Web & Devices offers the most efficient way to prepare images for Web use, since it automatically strips out all previews which can make your web images dramatically smaller compared with using File Save As… to save as a JPEG.
Web palette colors
The Web palette contains the 216 colors common to both platforms and is therefore a good choice for web publishing if viewers are limited to looking at the image on an 8-bit color computer display. Now to be honest, restricting your colors to a Web palette should not really be that necessary these days, but the option is still there. However, the Web Snap slider lets you modify the color table by selecting those colors that are close to being ‘browser safe’ and making them snap to these precise color values. The Web Snap slider determines the amount of tolerance and you can see the composition of the color table being transformed as you make such an adjustment.
GIF Save for Web & Devices
The GIF Save for Web & Devices options (Figure 14.12) are also quite extensive. You have the same control over the image size and can preview how a resulting GIF will appear on other operating systems and browsers – the remaining options all deal with the compression, transparency and color table settings that are specific to the GIF format. The choice of color reduction algorithms allows you to select the most suitable 256 maximum color palette to save the GIF in, which includes the 8-bit palettes for the Macintosh and Windows systems. These are fine for platform-specific work, but such GIF files may display differently on the other system's palette. The Perceptual setting produces a customized table with colors to which the eye is more sensitive. The default Selective setting is similar to the Perceptual table, but more orientated to the selection of web safe colors. This is perhaps the best compromise solution to opt