I would like to request a filter with the ability to take a scan of a half-tone image (B&W, CMYK, etc) and automatically blend and fill the gaps for a smoother, clearer image.
Normally this is accomplished manually by blurring the image, but I've found that more often than not I end up losing detail when working with hi-res images. Using the JPEG artifact removal filter to clean up after sometimes helps, but not by much.