Here’s a simple Tutorial to help you create a dual-toned image.
Step 1: Fire up Photoshop and open up your image. I am using Elisha Cuthbert’s picture, you wouldn't know what I went through making this tutorial cause I didn’t feel like spoiling her beautiful face… I'm such an idiot.
Step 2: Go to Image > Adjustments > Threshold. This will bring up a dialog box with a histogram. Don’t pay much attention to the histogram. Just make sure that features of the face can be seen properly like the lips, nose and eyes. My magic number was 155.
Step 3: Next we diffuse the sharpness of the image. Go to Filter > Stylize > Diffuse. In this box just select “Anisotrophic� and click on okay.
Step 4: Since the diffuse filter blurs the image out, you need to sharpen it again using the Filter > Sharpen > Unsharp Mask Filter. Give a value according to what you feel looks right. I gave something like 95/50/4.
Step 5: Bring up the Hue/Saturation dialog box (Ctrl+U). Check the Colorize box in the lower right and then move the hue slider to the desired colour, Saturation for…Saturation and give it a little bit of lightness.
You’re done!
Try this effect with an image with no background (white), has a different feel to it. Didnt' have any pics at hand to demonstrate that though...