This is what I did years ago:
This is all I've managed since yesterday:
Seems I have forgotten how I did this a couple years back. I'm using PP. I can't smooth those edges as much as I need to.
I thought all I had to do was repeatedly apply the Remove Noise effect, up to a dozen times or so. Whatever I did, I clearly remember that I saw the edges smooth out a bit more every time I applied the effect. EVERY TIME. I would stop when I thought the edges smooth enough for a kid to trace accurately.
Now, the edges smooth a bit the first couple times I apply the effect, but I reach a point at which the effect no longer works and these edges do not smooth any more. The smallest floating blobs do not disappear the way they did before. No normal kid could trace shapes as complex as those in the second image.
I can do something similar by using the Smooth effect several times, and then applying the Posterize transformation again, but I really do not remember doing it that way before. I don't remember a blurriness being part of the process. I could swear all I did was Remove Noise repeatedly, but maybe I'm not remembering clearly. It has been three years.
If you could reverse engineer what I did three years ago, I'd greatly appreciate it.
I've found a couple ways to do something similar to what I remember, but not repeat what I remember. I don't mean to confuse the subject, but will, because I last did this three years ago. I remember applying an effect repeatedly after posterizing the image. Every time I applied the effect, the edges would smooth out a bit more, the little positive and negative shapes would shrink or even disappear. I repeated the effect many times, until the image looked right. I can't remember which specific effect behaved this way. I thought it was simply Remove Noise, but that seems to work just a couple times, after which the image no longer changes. I do remember that whatever I did did NOT just stop working after a couple tries, but would continually degrade those edges more and more, every time the effect was applied. I could turn the faces into unrecognizable blobs, if I wanted. My lesson plan only mentions a "noise filter." And "Dust and Scratch." Shame on me for not being specific when I wrote it. The smoothing effects work the way I've described, but I do not remember making the image blurry at any point—just watching the edges gradually smooth out. Another wrench in the works may be that I last did this with CorelDRAW 11, not X5. Maybe there was a bug in the unpatched version that allowed the effect to continually eat away at those posterized outlines? A bit speculative, but that's all I can come up with at this point. I can remember hitting a shortcut combination over and over, watching the outlines smooth out a little at a time, and stopping when I thought it good enough. Any other ideas?
Have you tried using PowerTrace? (Bitmap > Outline Trace > Clipart...) I had a quick play with the settings and got this.