Sniper said:
Hi there,
I am using a nikon LS slide scanner to process
all of my old material into digital format and really enjoy the ease of
the Digital ICE feature which does a very good job of removing
dust/scratches etc. However, the big problem is that I have alot of old
B&W stuff which is not compatible with digital ICE.
Does anyone here know of a program which can
clean up B&W photos semi-automatically?. If not then I guess its back
to the old fashioned method of using the clone tool and photoshop!.
Thanks for any help,
Alex
This is a technique I learned of Ian Lyon's Computer Darkroom site. He
has since removed it, but generously emailed me a pdf of his tuturial.
Here is a text explanation I've cobbled together. It is just one tool
to be employed, but very handy for the small stuff, especially
overlaying detail:
Dust and scratch treatment using Photoshop's History Brush:
Preamble:
I've found the following best suited for dealing with isolated, small
diameter dust specks on a scan. It is invaluable where the dust
overlays complex patterns, where appling the clone stamp or healing
brush can be a nightmare. To set up, it is advisable to set history to
"non-linear".
Setup steps:
1. Open file. Ensure the history pallet is showing. By default,
Photoshop creates a snapshot at file open. If you are going to
immediately do the dust treatment procedure, this will do as snapshot
#1. If you want to do other things first, do so, and then create a
snapshot afterwards, just before starting the dust and scratch
treatment. This is accomplished via one of the little icons along the
bottom of the history pallet. Hover the mouse over each to determine
which is which.
2. Having created a snapshot (or using PS's), go on to apply
Photoshop's Dust & Scratch filter. I would suggest 5 radius and 0
threshold. Your image should become *very* soft.
3. Take another snapshot, snapshot #2.
4. Click on the the right side, large area of snapshot #1 (or PS's).
Your image should become sharp again. Then, click on the small, left
side square of snapshot #2. A little history brush icon should appear
in that square. What you have done is to revert to the sharp state, but
told Photoshop to use snapshot #2 as source for the History Brush. This
is the snapshot with the D&S treatment.
5. Set your current brush to be the history brush, either through the
tool pallet, or by typing "y". Now, if your dust specks are dark in
tone (the usual for slide scans), set the mode of the brush to
"lighten". If your dust specks are light in tone (the usual for
negative scans), set the mode of the brush to "darken". I would
recommend you set the brush diameter fairly small, say 20, and soft
edged. Leave opacity and flow at 100%.
Application:
Pick a small speck to treat. Assuming it is a dark speck, ensure your
mode is lighten. Apply a point application of the history brush,
centered on the speck. Photoshop compares the zone bounded by the brush
diameter, and *if* it sees lighter pixels in the snapshot the history
brush is sourcing from, it revises the values of those existing pixels
with pixels from the snapshot. In short, it lightens the speck area.
For specks up to maybe 10 pixel diameter, it is 100% effective, with
little or no apparent softening, simply because the area is so small.
For larger diameter specks, or scratchs, the softening *will* become
obvious, and those are better dealt with via the healing brush or clone
stamp.
