Brian Axe, a Google product management director, said, "We're excited to announce that Google has acquired Picnik, one of the first sites to bring photo editing to the cloud."
Google did not disclose the financial terms of the deal for Picnik.
Axe further said, "Google would not be announcing any significant changes to Picnik today, though we'll be working hard on integration and new features."
"Google would continue supporting all existing Picnik partners," he added.
Picnik allows users to import photos from other services such as Picasa, Flickr and Facebook.
In a blog post, Picnik said it had 20 employees and receives millions of visitors a month.
"Under the Google roof we'll reach more people than ever before, impacting more lives and making more photos more awesome," Picnik added.