When is photography art?

This photo was altered using Photoshop Elements and applying the filter called "glowing edges". I haven't changed the original photo other than adding this effect. It changes the appearance drastically, yet to me it offers another way of looking at the subject, in this case, grain elevators. It's not quite a painting and not quite a photo, but to my way of thinking, it's art.
Photographs have been altered ever since they were invented, so is this really any different? Now we can alter photos digitally, which probably wouldn't even have been considered if it hadn't been for the images manipulated by photographers prior to the digital age.
If you want to see any of my posted photos at at larger size simply click on the photo.