Recreating Anti-Alliasing/Moiré effects


I'm currently designing a poster, and when I view the design in Illustrator my Ben-Day dotted images are heavily distorted in their color and spatial appearance.

I really like this. Is there a way I could (possibly in Photoshop) recreate these distortions so they end up in my exported pdf?

This is how the poster looks when exported to png:

enter image description here

Here's a screen-shot from Illustrator:


4/3/2014 7:04:00 PM

Accepted Answer

If we look how the Moiré pattern is created we can see that it is the result of rotating linear patterns:

enter image description here
Soure: Wikimedia

This is mostly unwanted on fast method scaling of images that have a regular pattern, or on displaying such images on a display made up of regular patterns too (like our screens).

To intentionally produce this effect we need a source image dithered with a regular pattern such as the halftone dithering of the example given.

Below are steps to transform an image with adding Moiré:

  1. Dither source image using a regular pattern:

    enter image description here

  2. Copy the image and paste it as a layer on top of the dithered source

  3. Apply a rotation to the pasted layer (the angle will control the effect size)

    enter image description here
    Moiré overlay with transparency

    enter image description here
    Moiré overlay with 50% opacity

    enter image description here
    Moiré overlay with a line-dithered source

From examples above we can see that the primary dithering technique will deptermine the shape of our Moiré (diamonds produce diamonds and lines will produce lines).

4/3/2014 1:12:00 PM