February 28, 2013
BallCam Utilizes Algorithms And GoPro Camera To Provide New Field Of View
[ Watch the Video: BallCam: GoPro HD inside a football ]
Lee Rannals for redOrbit.com - Your Universe Online
Researchers took a rubber-sheathed plastic foam football, similar to a Nerf football, and embedded a GoPro HD camera in the side of it so they could record video while the ball was in flight. A spiraling football and a video camera might seem like a headache to watch, but an algorithm developed by the team converts the raw video into a stable, wide-angle view.
The BallCam's algorithm allows the 600 rpm spinning footage to become useful footage, whether to eventually use it for professional sports for TV, movie productions or training purposes.
Kris Kitani, a post-doctoral fellow in Carnegie Mellon's Robotics Institute, told redOrbit in an email that the project started in the greater context of research known as "Digital Sports," a term first coined by Professor Hideki Koike at the University of Electro-Communications in Tokyo, Japan. This research project looks into the integration of technology with sports, and Kitani said they particularly want to know how technology can be used to augment the spectator experience, analyze athlete activities, and create new sports that integrate technology.
"The current BallCam (a camera in an American Football) could be used to generate replay videos of a wide receiver grasping for the ball," Kitani told redOrbit. "You can probably imagine the extensions to other types of ball-based sports like soccer. You could see the goalie jump for the ball as it's being kicked toward the goal."
Other researchers have developed throwable cameras that produce static images, or use multiple cameras to produce a stabilized video, however, Kitani and researchers were able to use a single camera with a narrow field to generate a wide-angle video.
Once a passer throws the ball in a clean spiral, the camera records a succession of frames as the ball rotates. The researchers' algorithm then goes to work, using the sky as a way to determine what is up, and what is down. The upward frames are discarded, and the remaining frames are stitched together with special software to create a panorama.
The team's algorithm also makes corrections for some distortions in the image that twist yard lines due to the ball's fast rotation. Kitani said a faster camera sensor or other techniques could be used in the future to reduce even more distortion.
Kitani told redOrbit they have also dreamed up a few other ideas for the ball, other than professional sports.
"Other applications, we entertained early on in the process was to use the ball for local area mapping. For example, imagine you are in a parking lot and you are looking for an open spot," he said. "You can throw this ball up in the air and it might be able to tell if there are any open parking spots nearby."
For now, the ball has a square hole cut into it to fit the camera, so it is not ideal for football players to start using. However, Kitani said there could be a way to make the camera more discrete, so it would not bother quarterbacks or wide receivers trying to catch the football.
"The camera positioning in the prototype is not very stable so having a specially designed ball with slots for the cameras and plastic covers over the lens could make it easier to handle the ball (and protect the cameras)," he told redOrbit.
Kitani said bringing a new perspective for the fans to watch their favorite sport isn't the only interest they have in bettering the experience.
"The BallCam has focused on the visual aspect of the spectator experience but we are also interested in augmenting the haptic (touch) experience. Wouldn't it be cool if a device, like the vibration device on your cell phone, could allow you to experience the impact of the ball as it gets smashed by players on the field? This is another direction of research we are pursuing," he told redOrbit.