I posted about this problem a while ago and got zero response, so am
attempting to reformulate the question (see last paragraph):

I am currently applying a rather large gaussian blur to a scanned image. All
looks fine. I then apply a little bit of noise to remove stepping/banding of
colour. 'The anomaly' (see next para) is just visible... but only just, at
200%, if i squint, look away and surprise it etc. I then convert to
printer/paper profile (which looks pretty much the same) and print on Epson
1290.

It is when printed that 'the anomaly' really appears: there is a blend from
(coincidentally) about skin tone to green, and about halfway through the
blend there appears in the print a band of much brighter green, almost like
a halo. Sadly this is totally unacceptable, and cannot be manually corrected
because (for reasons I won't go on about here) the image has to be almost a
clone of another image (which I am also preparing and which also suffers
from the anomaly) and any difference between the two images will be
instantly visible. Any corrections have to be mechanical so that they can be
applied to both images identically.

It doesn't matter if I do the GB in 16it, whether i do or don't apply noise
(unless i apply so much that it becomes a problem in itself), or whether i
work in the printer colour space.

Incidentally, if i do a mode change to CMYK then I do see the anomaly, but
all the other colours are much more horrid than the RGB to printer profile
conversion, and getting them back would introduce loads more differences
between the 2 images (probably).

Is there some other similar kind of blur effect that I could use (that I
have severity control over), or some other way of getting the same effect
but without the halo, or correcting the halo?

My head hurts from banging it against that brick wall... any one else any
ideas?

Giles Stokoe

photographer/photojournalist. See some images at http://www.stokoe.co.uk


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

Reply via email to