Apply Halftone Effects in Gimp

Sometimes halftone effects are useful in graphic design applications. Halftone is essentially reproduction of an image where changes in tone are produced by changes in dot size and/or spacing. There are various halftone methods that come from the printing world such as staying in greyscale or using CMYK color models. Applying halftone effects to an image is fairly straight forward in Adobe Photoshop using the Apply Halftone Method, but not so straight forward in Gimp. In Gimp, halftone effects are produced by going to Filters - Distorts - Newsprint... I'll take you through a quick tutorial using a sketch of a skull I did a while back:

My Original Skull to Apply Some Halftone Effects To

One thing to note that when applying halftone filtering is that it works much better on soft, blurred edges then sharp edges. Let's duplicate our layer and then apply a Gaussian Blur to soften everything before applying any halftone. Go to Filters - Blur - Gaussian Blur... to bring up the Gaussian Blur dialog:

Gaussian Blur Dialog

For this example, I am going to blur the image by 25 pixels. We now have a blurry skull ready to apply halftone to:

Our Blurry Skull

Next, bring up the Newsprint Dialog by going to Filters - Distorts - Newsprint... There are a couple settings to get used to that can create some different results. One useful setting is the cell size. The smaller this value is, the smaller your dot objects will be, and thus the finer the resolution the halftone image will have. There are three modes to separate the image into dots with this particular filter: RGB, CMYK, and Intensity. For this example, we'll stay with RGB and align the angles of each Red, Green, and Blue component to 0 to product essentially black dots. The spot function can be changed as well from dots to things like lines for some neat results. Here is our Newsprint Dialog:

Newsprint Dialog

I am going to apply this affect a few times to multiple layers, turning white to transparent to produce a more 'complicated' effect of halftone rather then just doing it once. Our first execution of it will be for very small, 3 pixel sized dots:

First Pass of Newsprint Filter

I have a duplicate of our original skull layer and will now apply a larger cell size to create bigger dots:

Second Pass of Newsprint Filter

I will now run Newsprint on another Layer and invert it for a 'White Dot' effect. Here is a view of the multiple layers of the skull I now have:

Example of Multiple Halftone Layers

We now have a fun little halftoned skull that might be useful for something. Sometimes halftone is useful for retro effects since it originates from one of the first printing methods. Our skull has significantly less color depth but can be made out by the various dot combinations!

Our Final 'Halftoned' Skull

That's it! Many different effects can be achieved by playing with the settings in the Newsprint filter. Besides this skull, I'll leave you with another example of an image with a halftone effect applied to it. This time it is just a background layer around the actual artwork:

Another Illustration with Halftone