>> I was hoping, but not expecting, for a simple scanner trick but I
understand
the problem and I have to setup all the camera equipment. <<

Bertho, for those of us with only a flatbed...what to do?

Richard - does a drum scanners focused spot lightsource and drum mounting
overcome the white spot problem on textured reflective contone photo prints?
The directional lightsource of the flatbed scanner and is a big problem...

There are two basic answers to this problem if you only have a flatbed and
Photoshop with no option to shoot a copy shot.

i) Scan once, attempting to place the longest edge perfectly against the
scanners ruler edge. Rotate the original 180 degrees and scan again...or
experiment with 90 degrees and scan again. Using the same scanning settings
so as not to have auto colour difference issues between scans etc. The key
is to scan as straight as possible on both scans. This changes the
lightsource/scan angle relative to the original...

In Photoshop, flip/rotate etc the second scan to match the first. Layer the
two files together. Change the upper layer to difference blend mode to align
the two images. A black image = perfect registration, which is not likely.
You may need to dupe the layer and mask sections and fudge the other dupes
into different positions etc to do this. Or you may have to
transform/rotate/scale-distort the second scan a little etc. When happy
change from difference blend to DARKEN layer blend mode and then toggle the
view of the layer on/off to see if you are happy.

ii) This only uses one scan. A duped layer is filtered to remove the spots
without damaging the detail too much. This could be grain reduction actions
or plugs/applications dedicated to noise removal (Neat Image, Noise Ninja
etc).

This process layer is blended in darken mode to remove the spots. One can
add layer masks and or blend if layer sliders etc to restrict the edits.
There are many possibilities and variations of the theme.

Another option is to do a second scan at the same physical rotation as the
first, this time only changing the software settings to use DECREE and
then to layer/blend/mask as above.

As darken blend mode only alters lower pixels which are lighter than the
upper layer one gets the best blend of the lesser quality noise processed
layer into the original sharp scan. In effect it is spotting out each
individual spot.

One may also wish to see what pulling a darken midtone or darken shadow
endpoint level/curve on the darken blend layer does...

This technique can also be used in Lighten blend mode to reduce dark spots
on light backgrounds.

This is a good way to retain maximum quality with the least manual work, but
it is more for the special image than a production job of many scans.

One final option may be to scan at a higher resolution and at the original
physical size/magnification and then to resample down smaller to the final
print size/resolution as the first step. This may help reduce the noise/dust
and save you work/time...but will not result in the best 'raw' data as the
above methods which take more time and effort.

Some similar ideas are presented here:

http://members.ozemail.com.au/~binaryfx/IT_scanningspotting.html

Regards,

Stephen Marsh.

===============================================================
GO TO http://www.prodig.org for ~ GUIDELINES ~ un/SUBSCRIBING ~ ITEMS for SALE

Reply via email to