I have maps with gray nations.  For the printer these need
to be halftone.

I can laser print and produce a halftone, then scan at high
resolution to get a halftone image.  This works in principle but
not very good in practice on my machines.

Is there any way to convert gray to halftone directly in PSP?

I know the "reduce to two colors" is a possibility but the
printer may not like Stucki, Floyd, Burkes dots.

If my printer can make halftones, why can't PSP?

Mason C

"Mason C" <masonc2XXX@XXXearthlink.net> wrote in message
news:6fbi93pone20n62v8j5d7dqt4nbusb7n6i@4ax.com...
>I have maps with gray nations.  For the printer these need
> to be halftone.
>
> I can laser print and produce a halftone, then scan at high
> resolution to get a halftone image.  This works in principle but
> not very good in practice on my machines.
>
> Is there any way to convert gray to halftone directly in PSP?
>
> I know the "reduce to two colors" is a possibility but the
> printer may not like Stucki, Floyd, Burkes dots.
>
> If my printer can make halftones, why can't PSP?
>
>       Mason C
Its more an effect then the use of a Line screen But effects artistic
halftone will add dots.

Trev wrote:
> "Mason C" <masonc2XXX@XXXearthlink.net> wrote: 
>
>  Its more an effect then the use of a Line screen But effects
> artistic halftone will add dots.

You have chosen not to reveal your version, but PSP 8 and later set
the screen properties with this Effects > Artistic Effects >
Halftone. There's a plug-in for earlier versions.
--
Fred Hiltz,  fhiltz at yahoo dot com

On Sat, 14 Jul 2007 20:16:42 GMT, Mason C
<masonc2XXX@XXXearthlink.net> wrote:

>I have maps with gray nations.  For the printer these need
>to be halftone.
>
>I can laser print and produce a halftone, then scan at high
>resolution to get a halftone image.  This works in principle but
>not very good in practice on my machines.
>
>Is there any way to convert gray to halftone directly in PSP?
>
>I know the "reduce to two colors" is a possibility but the
>printer may not like Stucki, Floyd, Burkes dots.
>
>If my printer can make halftones, why can't PSP?
>
>       Mason C
All versions can do a color reduction.

as an example, in v7, do a
Colors>Color Reduction>2

Set Gray, then Error Diffusion with one of the 3 modes:
Floyd, Burkes, or Stucki

Then weighted or un weighted.

I'd make up a test image of combinations of the 3 x 2 selections and
print to see which reduction creates the most pleasing effect on your
printer.  And be sure to print at one pixel to one printer dot to get
the best effect.

Set the size of the image first, using your printer's dpi value to set
the PPI value in PSP.   Then do the above conversion.

Ron

On Sat, 14 Jul 2007 20:16:42 GMT, Mason C <masonc2XXX@XXXearthlink.net> wrot
e:

>I have maps with gray nations.  For the printer these need
>to be halftone.
>
>I can laser print and produce a halftone, then scan at high
>resolution to get a halftone image.  This works in principle but
>not very good in practice on my machines.
>
>Is there any way to convert gray to halftone directly in PSP?
>
>I know the "reduce to two colors" is a possibility but the
>printer may not like Stucki, Floyd, Burkes dots.
>
>If my printer can make halftones, why can't PSP?
>
>       Mason C

PSP 8.01     "Effects artistic halftone"  is what I needed.

I had looked in Help for "halftone" and found nothing so
assumed there was nothing.  I might never have found it.

Thanks ever so much for all the time you've saved me.

Mason C         ( I'll post my book someday )

awww, cheez, I posted the wrong place !

On Sun, 15 Jul 2007 04:43:22 GMT, RonV <RonVick@Nospam.com> wrote:

>On Sat, 14 Jul 2007 20:16:42 GMT, Mason C
><masonc2XXX@XXXearthlink.net> wrote:
> 
>All versions can do a color reduction.
>
>as an example, in v7, do a
>Colors>Color Reduction>2
>
>Set Gray, then Error Diffusion with one of the 3 modes:
>     Floyd, Burkes, or Stucki
>
>Then weighted or un weighted.
>
>I'd make up a test image of combinations of the 3 x 2 selections and
>print to see which reduction creates the most pleasing effect on your
>printer.  And be sure to print at one pixel to one printer dot to get
>the best effect.
>
>Set the size of the image first, using your printer's dpi value to set
>the PPI value in PSP.   Then do the above conversion.
>
>Ron

Thanks for the suggestions.

I should have explained that it is the Book Printer corporation that
expects halftone.  My personal printer is somewhat beside the point.
Not to say that Floyd et al "dots" might not work.

A constant dot shape and spacing (halftone), and perhaps a certain
angle, may be desirable or necessary for the printing press.

Mason C

On Sat, 14 Jul 2007 20:16:42 GMT, Mason C
<masonc2XXX@XXXearthlink.net> wrote:

>I can laser print and produce a halftone, then scan at high
>resolution to get a halftone image.  This works in principle but
>not very good in practice on my machines.

If you need vector output (PostScript) of halftone you can use this:

http://www.ransen.com/repligator/Newsprint.htm

The rasterised images are not such a good demonstration though.




Easy to use graphics effects:
http://www.ransen.com/

On Sat, 14 Jul 2007 20:16:42 GMT, Mason C <masonc2XXX@XXXearthlink.net> wrot
e:

>I have maps with gray nations.  For the printer these need
>to be halftone.
>
>I can laser print and produce a halftone, then scan at high
>resolution to get a halftone image.  This works in principle but
>not very good in practice on my machines.
>
>Is there any way to convert gray to halftone directly in PSP?
>
>I know the "reduce to two colors" is a possibility but the
>printer may not like Stucki, Floyd, Burkes dots.
>
>If my printer can make halftones, why can't PSP?
>
>       Mason C

Trev and Fred got me onto Effects, Artistic Effects, Halftone and
thanks, it will work for me.

One slight problem: the half-tone dots join into the border lines with
the effect of thickening the lines in an irregular way.  (this doesn't
happen if I print the gray graphic and scan it -- tedious halftone)

I wonder if anyone has a solution to this problem. I've made a
few experiments with blurring etc. with no success.

Mason C

Mason C wrote:
> On Sat, 14 Jul 2007 20:16:42 GMT, Mason C
> <masonc2XXX@XXXearthlink.net> wrote:
> 
>
> Trev and Fred got me onto Effects, Artistic Effects, Halftone
> and thanks, it will work for me.
>
> One slight problem: the half-tone dots join into the border
> lines with the effect of thickening the lines in an irregular
> way.  (this doesn't happen if I print the gray graphic and
> scan it -- tedious halftone)

That is hard for me to visualize, but guessing at what you are
seeing, how about adding the border after making the halftone
effect? Apparently you do not want the border itself to be halftone.

Could you post a sample image somewhere, or switch to the Corel PSP
newsgroups where attachments are permitted?
--
Fred Hiltz,  fhiltz at yahoo dot com

On Sun, 12 Aug 2007 10:57:52 GMT, "Fred Hiltz" <not@home.ca> wrote:

>Mason C wrote: 

snipped extraneous
 
>
>That is hard for me to visualize, but guessing at what you are
>seeing, how about adding the border after making the halftone
>effect? Apparently you do not want the border itself to be halftone.
>
>Could you post a sample image somewhere, or switch to the Corel PSP
>newsgroups where attachments are permitted?

I looked at Corel groups and found things confusing -- I try later.

Here's a sample:

http://home.earthlink.net/~frontal-...ftonesample.gif

Along the lines are large dots that make the line look rough and
thicker.

My procedure:

1. On an outline drawing (think map of U.S. showing states)
I fill in the areas with four well-chosen light colors.

2. In Effects, Artistic Effects, Halftone I use  "Round 6 dots,
RGB all at same angel, check and Overlay 100"

Then with some labor I reduce this to black and white.

The result is ok except for the annoying dots on the lines.
It seems that the PSP halftone algorithm wants to halftone the
black lines.  The printer does not do this when it halftones
gray areas.

I do not know how to add border lines to an area having
only different colors to distinguish them.  Magic wand will
delineate them, but then what to do?     And if the area is
only dots the wand won't work.

Mason C