Adobe 29180155 User Guide - Page 269

ADOBE PHOTOSHOP ELEMENTS 4.0 264 User Guide Adaptive Creates a custom color table by sampling colors from the spectrum appearing most commonly in the image. For example, an image with only shades of green and blue produces a color table made primarily of greens and blues. Most images concentrate colors in particular areas of the spectrum. Restrictive (Web) Uses the standard, 216-color, web-safe color table common to the 8-bit (256-color) palettes of Windows and Mac OS. This option ensures that no browser dither is applied to colors when the image is displayed using 8-bit color. If your image has fewer than 216 colors, unused colors are removed from the table. 5 To specify the maximum number of colors in the color palette, select a number from the Colors menu, enter a value in the text box, or click the arrows to change the number of colors. If the image contains fewer colors than the palette, the color table reflects the smaller number of colors in the image. 6 If you chose Restrictive (Web) for the color-reduction algorithm, you can choose Auto in the Colors menu. Choose Auto if you want Photoshop Elements to determine the optimal number of colors in the color table based on the frequency of colors in the image. 7 Choose a dithering percentage, either by entering a percentage in the Dither text box or by clicking the Dither menu arrow and dragging the slider that appears. 8 If the image contains transparency, select Transparency to preserve transparent pixels; deselect Transparency to fill fully and partially transparent pixels with the matte color. 9 To create an animated GIF, select Animation. 10 To save your optimized image, click OK. In the Save Optimized As dialog box, type a file name, and click Save. See also "About dithering" on page 268 "About GIF format" on page 260 "About PNG-8 format" on page 260 "About transparent and matted web images" on page 265 "To create an animated GIF" on page 265 To optimize as PNG-24 PNG-24 format is suitable for compressing photographs. However, PNG-24 files are often much larger than JPEG files of the same image. PNG-24 format is recommended only when you work with an image that includes multiple levels of partial transparency. 1 In the Editor, open an image and choose File > Save For Web. 2 Choose PNG-24 for the optimization format. 3 Select Interlaced to create an image that is displayed at low-resolution in a browser while the full-resolution image is downloading. Interlacing can make downloading time seem shorter and gives viewers feedback that downloading is in progress. 4 If the image contains transparency, select Transparency to preserve transparent pixels; deselect Transparency to fill fully and partially transparent pixels with the Matte color. 5 To save your optimized image, click OK. In the Save Optimized As dialog box, type a file name, and click Save.