Just thought I'd post my technique for dust and scratch removal. I know people may have tried this before, but I found this to work very well on my 40 year old kodachromes with a lot of dust and fungus etc. This works best on color pics and does not for some reason work that well on B&W.

I have the Polaroid 4400 plus film scanner but this should work with any. Note that the Digital ICE etc bundled with the Nikon scanners do not work with kodachromes. Go here to download the polaroid utility if you do not have it. http://www.polaroid.com/service/software/poladsr/poladsr.html

I have created an action for this workflow and now it takes less than 30 seconds for me to clean up a 104Mb scan.

1. Open the scanned file
2. Convert to 8 bit if not already done (this is not necessary for the filter to work, but is needed if you wish to automate using an action with the fill command).
3. Take a snapshot in the history panel - snapshot 1
4. Image>adjustment>Brighness and contrast>reduce brightness by 10 and increase contrast by 10 (this brings out the dust even more). Do not use layers as this is simpler.
5. Filter>Polaroid>dust and scratch removal. The settings are very important. I use the following: tile size =3 or 4; light dust and adaptive filtering =both unchecked; defect level =2 or 3; mask size =1; feathering =1.

Using a 100% view, you will notice there is almost NO blurring of the image itself with the above settings.

6. Image>adjustment>brightness and contrast: reverse what you did in step 4 above - increase brightness by 10 and reduce contrast by 10.
7. Take another snapshot in history - snapshot 2.
8. Click on snapshot 1 in the history panel to go back to the original state in step 2.
9. Click on the small square to the left of snapshot 2 in history (you should see the history brush icon here now).
10. Making sure the snapshot 1 is still highlighted, go to Edit>fill>contents =from history; opacity=100%; blending mode=normal.

You should now see the entire image come up clean. Discard the snapshot 2, and save the image. You could convert it back to 16 bit if you want to adjust color cast etc. Also, there may be some spots left which do not go away, use healing brush for those.

The entire process above can be made into an action. I could email it to anyone if you would leave your email address in response to this post.

I have also simplified some other retouching processes which I could outline as a workflow. I hope this helps someone. It took me a long time to get this working.

Pradeep

Attached samples at 100% crop of a kodachrome from 1959, before and after applying above workflow. Note the complete absence of the dark dust particles with no blurring of the face or sari. The larger spots are fungus and big scratches which can be easily removed with the healing brush or patch tool (my preferred method).

http://images2.fotki.com/v18/photos/4/44472/213638/Polaroidfiltertest2-vi.jpg)

http://images2.fotki.com/v18/photos/4/44472/213638/Polaroidfiltertest2_post-vi.jpg)