Benday dots are the little dots that printers used to use to transfer colour to newsprint without saturating the low-quality newsprint paper. There are very complicated ways to create a Benday-dot picture, but you can get the same effect in a few steps using a simple portrait of low quality (72 dpi) and Adobe Photoshop 7.0®. The results will be a cartoon-like image with black Benday dots and colour. A little practice using the program goes a long way.
Choose a portrait without too much background from your JPEG images. Save as "Benday" and close the original portrait. Click on "Filter/Artistic/ Poster Edges" to put black lines around the main images in your portrait.
Right-click on "Background" layer in the layers palette ("Window/Layers") and choose "Duplicate Layer." Choose "NEW" and name it "Dots." A new image will appear on your screen. On the "Dots" image, choose ("Image/Mode") "Grayscale" and discard colour information.
Adjust the "Dots" image, using "Image/Adjustments/Brightness/ Contrast," to delete most of the in-between colour (but not all). This image was created with +38 for "Brightness" and +63 for "Contrast."
Change the "Dots" image ("Image/Mode") to "Bitmap." For "Method" use "Halftone Screen." The Halftone Screen Palette will pop up. Choose a "Frequency" (15 in this image) and an angle (45) and choose "Round" for the "Shape."
Change the "Dots" image ("Image/Mode") back to "Grayscale" with a size ratio of 1. The image will stay black and white. Change the "Dots" image back to ("Image/Mode") RGB. In the "Layers" palette, right-click on the background layer and duplicate the layer, choosing the "Benday" document as its destination.
In the "Benday" image, adjust the "Opacity." (You can find it at the top of the "layers" palette). When you click on the arrow to the right of 100%, a sliding scale will appear below. You will be able to see how much colour is showing through as you slide the scale down and back. (This portrait was created with 40%, so the colours would be visible through the top layer.) Flatten the image ("Layer/Flatten Image") and save it as a JPG in your files. Discard the "Dots" image, if you wish, as it is no longer needed.
There are more complicated and perhaps more effective ways of achieving results that look like Benday dots in Adobe Photoshop and other programs, but this method is simple enough to create your own "cartoon" images. Through experimentation with some of the adjustments above, you can achieve other effects as well.