San Diego-based Nik Software, the developer of a popular set of photo filters and plug-ins for photo editing, has been acquired by Google. Financial terms of the acquisition were not disclosed. Nik Software has its corporate headquarters in San Diego, and also has operations in Germany. The firm's photo filters connect into Adobe Photoshop, Lightroom, and Aperture, and includes such products as Dfine, Viveza, HDR Efex, and more.