Among the many temptations of the digital age, photo-manipulation has proved particularly troublesome for science, and scientific journals are beginning to respond.

Some journal editors are considering adopting a test, in use at The Journal of Cell Biology, that could have caught the concocted images of the human embryonic stem cells made by Dr. Hwang Woo-suk.

At The Journal of Cell Biology, the test has revealed extensive manipulation of photos. Since 2002, when the test was put in place, 25 percent of all accepted manuscripts have had one or more illustrations that were manipulated in ways that violate the journal’s guidelines, said the executive editor, Michael Rossner of Rockefeller University in New York.

The editor of the journal, Ira Mellman of Yale, said that most cases were resolved when the authors provided originals. “In 1 percent of the cases, we find authors have engaged in fraud,” he said.

It’s important to understand the other 99% probably results from vanity and the always-popular urge to fiddle.