Changing the appearance of bitmap images with filters and effects


    Filters and effects let you apply a special look to bitmap images as well as vector objects. For example, you can apply an impressionistic or mosaic look, apply lighting changes, distort images, and produce many other interesting visual effects. (See Summary of filters and effects.)

    The following are a few things to consider when applying filters or effects to bitmap objects specifically:

    • Filters and effects don't work on linked bitmap objects. If you apply a filter or effect to a linked bitmap, it is applied to an embedded copy of the bitmap instead of to the original. To apply the filter or effect to the original, you can embed the bitmap in the document. (For information on embedding images, see Embedding linked artwork.)
    • Adobe Illustrator supports plug-in filters and effects from Adobe products such as Adobe Photoshop and from non-Adobe software developers. Once installed, most plug-in filters and effects appear in the Filter and Effect menus and work the same way as do built-in filters and effects. (For information on installing and developing these plug-in modules, see Customizing your Illustrator workspace.)
    • Some filters and effects can be memory intensive, especially when applied to a high-resolution bitmap image.
    • When you apply a raster effect to a vector object, the effect uses the document's raster effects settings to determine the object's resolution. (See Specifying raster effects settings.)
    • Some filters and effects can only be applied to vector objects. To identify commands you can apply to bitmap objects, see Comparing filters and effects.

    Use the following techniques to improve performance when applying memory-intensive filters or effects:

    • Select the Preview option in filter or effect dialog boxes to save time and prevent unintended results.
    • Change the settings. Some commands, such as Glass, are extremely memory-intensive. Try different settings to increase their speed.
    • Make sure Illustrator has enough RAM allocated for performing tasks and for the scratch disk (the temporary disk space used to work with bitmap images).
    • If you plan to print to a grayscale printer, convert a copy of the bitmap image to grayscale before applying filters. Note, however, that in some cases, applying a filter to a color bitmap image and then converting it to grayscale may not have the same result as applying the same filter directly to a grayscale version of the image.

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