Applying Filters As Live Effects
In Lesson 1, you applied a filter to a bitmap image. When you apply a filter to a bitmap object, you are permanently changing the pixel values. If you do not like the results of adding the filter, you can undo your changes by choosing Edit > Undo. Once you save the file, you can't remove the effects of the filter.
You can apply a filter as a Live Effect. Filters applied as Live Effects can be edited or removed at any time. You can apply filters to selected pixels in the image, but you can apply a Live Effect only to the entire object.
To apply a filter as a Live Effect, select the bitmap object with the Pointer tool. If you are in bitmap mode, click the red circle with the white X at the bottom of the document window to exit the bitmap editing mode; then select the object with the Pointer tool. Then choose the filter from the Effects pop-up menu.