Convert photo to dots

Jewelry Discussion
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
www.nolimitations.com