In the unlikely event smokers have forgotten, the federal government is yet again stepping up its campaign about the dangers of smoking.

When the U.S. surgeon general's office released its report linking cigarette smoking to cancer in 1964, roughly half the adult population of this country were smokers.

Now, after decades of public health warnings, that number has fallen to about 20 percent of the population. That decline represents a huge societal shift in attitude toward smoking, one of the most successful public health education campaigns ever conducted.

Despite the success, medical professionals in government remain frustrated and outraged by their failure to reach the hard-core smokers. So they've adopted a new strategy — a hard sell for the hard core.

The federal government this week unveiled nine graphic images it will require cigarette manufacturers to include on their packages and advertising.

The images include a picture of a man blowing smoking through a tracheotomy hole in his throat, diseased lungs, rotted teeth and gums, a man breathing through an oxygen mask, even a corpse with a long surgical scar down his chest.

U.S. Health and Human Services Secretary Kathryn Sebelius said it's her hope that the "frank, honest and powerful" images will "encourage smokers to quit, and prevent children from smoking." They might also encourage smokers to buy a cigarette case to shield themselves from the ugly pictures.

Smoking is an expensive and unhealthy habit. Indeed, few know that better than smokers themselves. Nonetheless, they choose to continue or are unable to quit.

So the feds are pushing harder. Half of a package of cigarettes and 20 percent of each large cigarette ad will contain these new images starting in October 2012. They are ugly pictures for an ugly habit, but nothing smokers haven't seen before or heard about from friends and family many times before.