1% dots
Phil Brown
Does anyone know of any software or a plugin for Photoshop that will remove
a 1% dot (or smaller) but not change the 2% dot.
cheers
phil
Odysseus
experimentation shows that it's very hard, if not impossible, to place
separate points at the 1% and 2% levels. So here's a workaround, which
could be saved as an Action for easy reuse:
1) Make a new layer on top of the image you want to change.
2) Fill it with White.
3) In Layer Options, on the "Underlying" slider under "Blend If" (the
lower of two sliders) drag the black triangle from the left nearly all
the way to the right side; the number above should read about 252 or
253. (1% of 256 is 2.56; you want to be this much short of 255.)
Alternatively, the same thing could be done with an adjustment layer,
which has the advantage of a smaller file size, especially on a colour
image. Instead of a regular layer in step (1) make a Curves adjustment
layer. Instead of step (2) make the curve a horizontal line at the 0%
level by dragging the 100% end all the way to the bottom (this should
turn the whole image white). Step (3) is the same as above.
Either of these will have the effect of replacing all pixels of 1% or
lighter with White.
"We don't need no stinkin' plug-ins!"
--Odysseus
Lee Blevins
AJEngland
<phil....@mcg-graphics.com> writes:
>Subject: 1% dots
>From: "Phil Brown" <phil....@mcg-graphics.com>
>Date: Tue, 31 Jul 2001 09:08:20 +0100
You might want to look at PrintOpen - Heidelberg profile creation software. I'm
still using ver 2.5 (I believe ver 4.0 is current) and it supports minimum and
maximum dot limits. Using PrintOpen you could create a profile for your output
device that would turn a 1% dot to 0% without affecting the 2% dot.
Al England
Ross Printing Company
Spokane, Washington
http://www.rossprint.com
Tim Vanhoof
Does anyone have a workflow that will get a 1% dot onto paper?
Seriously. When I was learning we assumed that anything under 5% was
going to disappear.
Jono Moore
timva...@gmx.net wrote on 8/1/01 10:59:
> Does anyone have a workflow that will get a 1% dot onto paper?
> Seriously. When I was learning we assumed that anything under 5% was
> going to disappear.
1% will probably disappear, depends on the equipment. You should be able to
hold 2-3%. But yeah, by the time it hits the paper...
--
Jono Moore
Prepress Department - Hillside Printing & Copy Centre
3050 Nanaimo Street, Victoria, BC, Canada
Tel: 250.386.5542 Fax: 250.386.7838
prep...@hillsideprinting.com www.hillsideprinting.com
Del Tree
<timva...@gmx.net> wrote
>Does anyone have a workflow that will get a 1% dot onto paper?
>Seriously. When I was learning we assumed that anything under 5% was
>going to disappear.
I have to say this post puzzled me a lot too :-)
I wonder if "Phil Brown" will enlighten us as to why he would want to
remove a 1% dot in Photoshop?
I can't see any reason for it other than Lee's rather caustic
contribution about CM...
Regards,
--
Del Tree
Grafit
> Does anyone know of any software or a plugin for Photoshop that will
remove
> a 1% dot (or smaller) but not change the 2% dot.
It's all too simple, and it's built right into the Photoshop itself.
When you open 'curves' dialog box, standard curve will appear, right?
Note the small icons below the curve diagram to the right. First icon
displays bezier-like curve, second has a pencil icon.
Well, switch to the pencil icon. This 'pencil-mode' will allow you to draw
individual points on the correction curve. To the left of these icons you
will find text labels indicating 'input' values (related to the affected dot
percentage values from the original image) and the resulting 'output' values
(related to the resulting pct values with your correction curve applied).
Carefully draw the 0% point just a screen pixel or two away from the zero
point, and check if those text labels indicate 'input=1% output=0%' and
that's it.
My screen res is 1152*864 with 17" monitor, and I was able to hit the 1%
mark at the first try. I do have a Logitech hires optical mouse with the
extremely fine step resolution, but I believe this can be achieved even with
the less precise mouse, and the lower screen res will definitively be a
bonus.
If you fail to draw this curve, I have saved it and can send it to your
email :-)
Igor Draca
Studio Grafit
Split, Croatia
Grafit
> remove a 1% dot in Photoshop?
Because perhaps Quirk wouldn't let him auto-mask images on white background
that is not purely **white**...
Beacuse perhaps the image screens with diffuse (stochastic) screening
algorhytms or is to be printed on inkjet printers with error diffusion...
Because perhaps the image should serve for serious scientific density/dot
measuring color management purpose...
Because...
Because it's there but it shouldn't be there.
What bothers me is why the hell would he remove 1% dot but retain 2% dot
intact?
Mike Kouvchinov
> What bothers me is why the hell would he remove 1% dot but retain 2% dot
> intact?
Hi, Igor
I think he has printing process that make huge difference between 1% and
2%. An example from our real-life work is flexo printer, who has at
printout dirt at 1% dot areas and something about 10% at 2%. May be his
form process is not optimal - it does not matter at the moment. But he
demands that no film should have 1% dot. We had used tone-reproduction
curve at our RIP to resolve problem once and forever. In our case RIP
is Brisque, but similar options could be found at other brands too. And
I believe correction in RIP is better then in Photoshop due to RIP do it
automatically and with no option to do it with one element and forget
with the other one.
Best regards, Mike
Phil Brown
Sorry I have been away .
The reason we want to remove 1% and keep 2% is as Mike says
It is a limitation in flexo printing. With the advance of ctp it is now
possible to
make and hold a 1% dot however trying to consistently hold this on a flexo
press is very difficult.
Thanks for your interest and help
phil
"Phil Brown" <phil....@mcg-graphics.com> wrote in message
news:9k5ovg$3gm$1...@newsreaderm1.core.theplanet.net...
Del Tree
<phil....@mcg-graphics.com> wrote (snipped a bit)
>The reason we want to remove 1% and keep 2% is as Mike says
>It is a limitation in flexo printing.
Ah - flexo. Say no more :-)
--
Del Tree