Adobe 23101335 User Guide - Page 336

326 CHAPTER 12 Optimizing Images for the Web Resizing the image during optimization (Photoshop Save For Web dialog box) When optimizing an image in the Photoshop Save For Web dialog box, you can resize the image to specified pixel dimensions or to a percentage of the original size. Note: You can also resize an image by choosing Image > Image Size. (See "Changing the pixel dimensions of an image" on page 97.) To change the pixel dimensions of an image during optimization: 1 Click the Image Size tab in the Save For Web dialog box. 2 To maintain the current proportions of pixel width to pixel height, select Constrain Proportions. 3 Enter values for Width, Height, or Percent. The New Size text field displays the new file size for the image. 4 Choose an interpolation method from the Quality pop-up menu: • Jagged (Nearest Neighbor) for the faster, but less precise, method. This method is recommended for use with illustrations containing non-anti-aliased edges, to preserve hard edges and produce a smaller file. • Smooth (Bicubic) for the slower, but more precise, method, resulting in smoother tonal gradations. For more information on interpolation, see "About resampling" on page 96. 5 Click Apply. Controlling optimization (ImageReady) By default, Photoshop and ImageReady automatically regenerate the optimized image when you click the Optimized, 2-Up, or 4-Up tab at the top of the document (if you have modified the image since the last optimization), when you change optimization settings with the optimized image displayed, or when you edit the original image. In ImageReady, you can turn off auto-regeneration so that the last version of the optimized image remains in the image window until you manually reoptimize the image or reactivate auto-regeneration. This feature is useful if you want to edit the image without pausing for reoptimization with each modification. You can also cancel optimization while it's in progress, and preserve the previous image. When auto-regeneration is turned off, the Regenerate button ( ) appears in the lower-right corner of each optimized image view. A regeneration alert symbol also appears in the Color Table palette if the optimized image is in GIF or PNG-8 format, indicating that the color table is out of date. To turn Auto Regenerate on or off: In the Optimize palette, choose Auto Regenerate from the palette menu. A check mark indicates that the option is turned on. To manually optimize an image: Choose a method for optimizing: • Click the Regenerate button ( ) in the lowerright corner of the optimized image (if it appears).