LOS ANGELES ? Pop star Rihanna has broken her silence over her assault by ex-boyfriend Chris Brown, describing the "humiliation" she felt when a police photo of her battered face was leaked to the media.

In an interview in the December issue of Glamour magazine -- which crowned the Barbadian singer its woman of the year for 2009 -- Rihanna said she was shocked by the aftermath of the attack on the eve of this year's Grammy Awards.

R&B star Brown was sentenced to five years of probation and 180 days of community labor in August after pleading guilty to charges stemming from his brutal late-night attack on Rihanna.

Rihanna told Glamour she now wants to act as an unofficial spokesperson for victims of domestic violence.

"Domestic violence is a big secret," she said. "I want to give as much insight as I can to young women to help speak for them."

The 21-year-old "Umbrella" singer said she had dismayed that a photo taken by police showing her facial injuries ended up being leaked to the media.

"It was humiliating; that is not a photo you would show to anybody," she said. "I felt completely taken advantage of. I felt like people were making it into a fun topic on the Internet, and it's my life.

"I was disappointed, especially when I found out the photo was (supposedly leaked by) two women."

Rihanna said she was also unprepared for the media frenzy which followed the February incident.

"I felt like I went to sleep as Rihanna and woke up as Britney Spears," she said. "That was the level of media chaos that happened the next day.

"It was like, 'what, there are helicopters circling my house?' There are 100 people in my cul-de-sac? What do you mean, I can't go back home?"