How to make pattern-dithered bitmap (halftone) style pictures?

That is not ascii art. It is called a pattern-dithered bitmap (halftone). I did a quick image search a found the source for your cropped art that has more pixel detail (see below).

I made a very quick example using a crop from a screen capture of art that is in a similar style to the portion of your image.

I changed the image mode to "greyscale" and then changed it to "bitmap" (in Photoshop, you cannot convert RGB or indexed mode to bitmap); in the bitmap settings, I picked a low PPI (maybe 30), and chose "pattern dither."

The low PPI makes the pattern larger in proportion to the image dimensions, but it also results in a smaller image as measured by pixel dimension.

Because I reduced the PPI, I then stretched the image back to the original size.

I know this is an old post, but this is what popped up on google search when looking for more diffusion patterns, so I wanted to add my own take on this for whoever stumbles on this.

I used to only use the bitmap method in photoshop where you convert to grayscale and convert to bitmap and choose your pattern, but I had discovered a better way to do it using a pattern layer. It's rather simple - all you have to do is set the blend mode to hard mix. (make sure the image is desaturated or in grayscale mode). Also, you can change the fill % of the pattern layer to get a smoother blend if you need it.

You can still then convert it to a bitmap using the threshold option using the same dpi scale. But having control to quickly change what dithering pattern you use is a game changer. You can also change the scale and rotation of the pattern, which you can't do with the first method. (be mindful that photoshop resamples the pattern when doing this, so it can break the pixel level details of a pattern).

Here is a sample of a couple small dithering patterns I have made, and what they look like on an image:

Also, a quick guide on how to make them:

1. Create a very small document in Photoshop, probably less than 10x10 pixels, and turn on pattern preview.
2. Use the pencil tool at a 1 pixel size to paint in single pixels.
3. Starting with white, paint in the pixels you want at the highest threshold.
4. Set the color to 90% grey, and paint the next step down, and repeat for every level changing the value down by 10% each time.
5. You might not have used all values from black to white, so make a levels adjustment layer.
6. Hold opt while dragging the black point until the bottom level of the image appears.
7. Set the output levels to 20 and 235. (this is to compress the values to let full black and white to show, but you don't have to do this)

Ta-Da! You have your pattern. You can visualize what it looks like using a threshold layer, or you can just turn the image into a pattern and test it out on another image using the pattern layer like I mentioned.

I should add is that you don't have to stick to pixel level patterns. You can make larger tonal patterns, and get some pretty unique outputs from that as well. Here is another version with some larger tonal patterns I made:

Lastly if you want a full size image to show the sharp pixels of the dithering like in the watch dogs artwork, then just flatten the image, and upscale the image to 200% (or 300%, 400%, etc) with the resample mode set to nearest neighbor.

If any of you see this and want some of these patterns I made, let me know and I will send you them.

I sort of feel old now! But back in the days, there was a popular software called TheDraw that ANSI/ASCII artists used to create artwork. It's not a filter per se, but it will definitely make things easier should you want to go the way of creating your own! (if it still runs on modern computers that is...)

To get the wanted result, you must start from an image that has strong lines and uniformly colored areas between them. A cartoon is good term for this.

Then use an image to ascii translator (website or program). You get an intermediate result like this:

As you see, the toning in your photo isn't actually done by scattering ascii characters, but other bitmap patterns instead. That can be simulated by taking the intermediate result to Photoshop or GIMP. If the result from the translator is a GIF, convert it at first to normal RGB or 8 bit grayscale image.

Then goto Filter > Pixelate > Mosaic, select a fine only few pixel mosaic. Finally take the curves tool and adjust the contrast.

In the following screenshot the contrast is just adjusted. The mosaic size is 3 pixels. The image from the translator is about 900 pix wide.

The translator program used here is ASCII Generator v2. It allows one to select the font and which characters are used for generating the halftone ramp. The following example uses no recognizable characters, but a few maybe better patterns for this purpose. The font = Lucida Console. No mosaic filtering is used:

ADDENDUM: Other answers suggest straight away to discard ascii translators and to use some pattern halftone dithering method. (Ascii translator actually is a special case of it). Here's one simple method with the simplest possible pattern:

At first adjust your image to have high contrast. Then add a layer that has a black-white pattern. Here is 5x5 pixel black and white square fill just under painting with the pattern stamp:

Blur the pattern and adjust with the curves tool it's tone range to cover nearly black to nearly white:

Give to the blurred pattern layer blending mode = Hard light:

Merge the pattern and image layers. Increase it's contrast to create the wanted effect. If needed, the contrast can be stretched to extreme by applying Image > Adjustments > Treshold. See the result

:

Somehow smoother appearance is possible by using the curves tool instead of Treshold:

I found out how to do this using a pattern in Photoshop.

1. Create a new file that is 9 × 9 px

2. Create this shape using the Pencil Tool

   

3. Press "Edit → Define Pattern → OK"

4. Open image to put over

5. Right click on the layer with the image and press "Blending Options"

6. Click "Pattern Overlay"

7. Select the pattern you just made

8. Change the blend mode to "Darken"

9. Profit