[Inkscape-user] trace bitmap on filtered JPG image

Hi Friends, I was just playing around with a JPG, a filter, and Trace Bitmap. The filter is Filters menu > Image Paint and Draw > Posterize Basic. No matter what settings I use for that filter, for example Levels = 1 or Levels = 10 (which produce very different results) after I use Trace Bitmap, the result is identical to if I use Trace Bitmap with no filter at all. What gives? Doesn't Trace Bitmap "see" the filter? I can provide screenshots or examples, if necessary. Thanks for your help, brynn