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Convert photo to dots


#1

I hope somebody out there can help me! I’ve done this in the past,
but now I just can’t figure out how. I’m tearing my hair!I want to
convert a photo to a dot pattern (such as would be used for a
newspaper) in Photoshop so that I can etch it. How do I do it?

Thanks
Noel


#2

Halftone filter?

I suppose it depends what version of photoshop - where to find the
filter but in Pshop 7 it’s in Filter: Sketch: Halftone Pattern

Hope that helps,
Miche
http://www.sumiche.com


#3

Simple as can be, in Photoshop just use Filter, Sketch, Halftone
Pattern. Start with a clean image, adjust the dot size and the
contrast as needed. You may need to further adjust the contrast in
the Image, Adjustments and perhaps Invert the image. Sounds like fun.

Marlin


#4

I’m not sure if this is exactly what you want, but in Photoshop
Elements 3 you can try Filter–>Sketch–>Halftone pattern

Perhaps convert image to grayscale first.

Julia


#5
I hope somebody out there can help me! I've done this in the past,
but now I just can't figure out how. I'm tearing my hair!I want to
convert a photo to a dot pattern (such as would be used for a
newspaper) in Photoshop so that I can etch it. 

Print Gocco makes a doo hikey – it’s clear with dots on it – that
you take to the photocopier and copy your picture with. They may
still sell those somewhere.

But, since you want the 21st century version, the Photoshop term
you’re looking for is Half-tone, I believe.

You can find online tutorials and videos (free) at the sites You
Suck at Photoshop, and Tubetorial.

And, if they are still doing it, the Threadless store in Chicago may
have low cost Photoshop classes.

Elaine
http://www.CreativeTextureTools.com


#6

Noel,

It’s called “Halftoning” (or making a halftone image). You don’t say
what version of PS you’re using, so instructions are for version CS4.

There are two basic ways - the “filter” way and the pre-press way.
You may want to try both to see which gets you the desired effect.

The “Filter” way:

  1. Select the entire image you want to convert. (CTRL-A selects the
    whole image.)

  2. Convert your image to grayscale if it isn’t already. Image ->
    Mode -> Grayscale.

  3. Go to Filter -> Pixelate -> Color Halftone. Adjust the settings
    on the “max radius” to achieve the desired effect (4 px is the
    minimum setting).

The “Pre-press” way (per adobe help: http://tinyurl.com/c8xsf3)

  1. Choose File > Print.

  2. Choose Output from the pop-up menu, and click Screen.

  3. In the Halftone Screen dialog box, choose whether to generate
    your own screen settings: -

Deselect Use Printer’s Default Screens to choose your own screen
settings. -

Select Use Printer’s Default Screens to use the default halftone
screen built into the printer. Photoshop then ignores the
specifications in the Halftone Screens dialog box when it generates
the halftone screens.

  1. For a grayscale halftone, enter a screen frequency from 1 to
    999.999, and choose a unit of measurement. Enter a screen angle from
    -180 to +180 degrees.

  2. For a color separation, choose from the following options:-

To have Photoshop determine and enter the best frequencies and
angles for each screen, click Auto. In the Auto Screens dialog box,
enter the resolution of the output device and the screen frequency
you intend to use, and click OK. Photoshop enters the values in the
Halftone Screen dialog box.

Changing these values may result in moire patterns.

  • If you are using a PostScript Level 2 (or higher) printer or an
    imagesetter equipped with an Emerald controller, make sure that the
    Use Accurate Screens option is selected in the Auto Screens dialog
    box (or in the Halftone Screen dialog box, if you’re entering the
    values manually). The Use Accurate Screens option lets the program
    access the correct angles and halftone screen frequencies for
    high-resolution output. If your output device is not a PostScript
    Level 2 (or higher) printer or is not equipped with an Emerald
    controller, this option has no effect.Note: Some PostScript Level 3
    printers will ignore the Accurate Screens setting if the screen
    frequency is set too low (as determined by the printer). .
  1. For Shape, choose the dot shape you want. If you want all four
    screens to use the same dot shape, select Use Same Shape For All
    Inks.

Choosing Custom from the Shape menu displays the Custom Spot Function
dialog box. You can define your own dot shapes by entering PostScript
commands–useful for printing with nonstandard halftone algorithms.
For about using PostScript language commands, see the
PostScript Language Reference published by Addison-Wesley, or consult
the imagesetter’s manufacturer.

For optimal output on a PostScript printer, the image resolution
should be 1.5 to 2 times the halftone screen frequency. If the
resolution is more than 2.5 times the screen frequency, an alert
message appears. If you are printing line art or printing to a
non-PostScript printer, see your printer documentation for the
appropriate image resolutions to use.

  1. Click OK.

Hope this works for you!

Karen Goeller
No Limitations Designs
Hand-made, one-of-a-kind jewelry


#7

Noel,

There should be an option in Photoshop to “posterize” which makes
things into little dots.

For a MAC, go to Images on the desktop and then to Adjustments. The
posterize option is there. If you search on Photoshop’s HELP, search
for Posterize.

I hope this is what you are looking for.

Good luck!
karen christians


#8

Thanks to all who said this, but, oddly, the result of this still has
grays. I now know how to do dots (filter, pixelate, halftone) and am
still trying to figure out how to change the shape of the dots.

Noel


#9

Not sure about Photoshop but you can download the Open Source
equivalent, GIMP http://www.gimp.org, for free. In GIMP select from
the menu Filters ->Distorts ->Newsprint It gives you complete control
over each color individually plus a number of other factors.


#10
Thanks to all who said this, but, oddly, the result of this still
has grays. I now know how to do dots (filter, pixelate, halftone)
and am still trying to figure out how to change the shape of the
dots. 

In the posting of the above, the quote was dropped. What it said was,
do halftone in the sketch menu. That way, I get a sort of fake
halftone-look-alike that still includes gray. The point of halftone
if B&W that looks like gray but isn’t! Crazy Photoshop. Noel


#11

Hi Noel,

I’m sure you’ll get a variety of answers, here’s how I’ve done it.

If you are starting with a RGB image, go to the Channels menu, and
click on one channel at at time, to see which gives you the best
results, then delete the other two channels. (This usually gives you
a better image than if you just convert the image to grayscale.)
Then on the menu bar, go to Image, Mode. Click on Grayscale. Then
click on Bitmap. At some point you may want to play with the
brightness/contrast and the Unsharp Mask filter. When you do these
steps makes a difference. I’m using Adobe Photoshop CS2. I love the
Snapshot feature on the History Pallette, I can play around with all
the filters and contrast, take multiple snapshots, then pick the one
that works best.

I hope this helps!

Kate Wolf in Portland, Maine hosting wicked good workshops by the bay.
www.katewolfdesigns.com www.wolftools.com


#12

Go to the discussion forum sawmillcreek.org and search for the
"Gold Method". It is an action created for Photoshop for preparing an
image for laser etching. I think it should do what you are after.

Chris


#13

Noel,

It’s called Halftone. I use Photoshop for this. Open your image then
use the menu sequence: Filters>Pixelate>Color Halftone then play with
the controls until you get the effect you are looking for. If you are
looking for the “color cartoon” effect you will have to posterize the
image first: Image>Adjustments>Posterize, then do the halftone. You
can also use the Filters>Sketch>Halftone Pattern but this is
grayscale only.

RC2


#14

The technical term is halftone. The easiest way is with a postscript
printer. Just set the screen frequency in the postscript area of the
printer dialog box to how coarse or fine a dot pattern you require.
30 is pretty coarse, 100 - 150 will probably work for your
requirements.

Go Script is a free software that should give you similar results if
you don’t have a postscript printer.

In an earlier life I was a photo engraver. We used nitric acid to
etch zinc printing plates by the Dow- etch process. For light
etching, ferric chloride etches copper quite nicely. It can be found
at most electronic stores.

Have fun!
Rod Grantham


#15
oddly, the result of this still has grays. I now know how to do
dots (filter, pixelate, halftone) and am still trying to figure out
how to change the shape of the dots. 

I figured Noel knew how to use halftone from the original post -
Photoshop 101. There are thousands - nay, tens of thousands - of
plugins for Photoshop, a large portion of which are free. Those are
the things that make it look like a duck but bark like a dog.
Perhaps/surely something more of a custom halftone lies there.
Google photoshop plugins… When the vast arsenal of native tools
just isn’t good enough…

http://www.donivanandmaggiora.com