New Focus for Digital Photography
Software that gives users more control of a camera could revolutionize photography.
Camera-phone owners can use new software to reprogram these devices–and capture images that would previously have been impossible to get.
Stanford University researchers have made software for the Nokia N900 phone that gives developers, and users, greater control over the phone’s camera components than ever before. This software makes a variety of apps possible. Using the software, developers have already created apps that can capture both light and dark parts of a scene, stitch panoramic photos together automatically, and capture extremely sharp photos even in low light.
Digital photography is normally constrained by the software built into the camera by its manufacturer. A field known as “computational photography” expands the possibilities of digital photography. It does this by using software to provide the user with more control over a camera’s components. Prior to the release of the new Stanford software, this kind of control has meant tethering that ca
mera to a laptop. “That doesn’t make it easy to try out our ideas in realistic settings,” says Levoy.
Levoy and colleagues have also developed Frankencamera–an experimental, portable computational camera designed to be similar to a conventional one. Y
et another way to expand the reach of this new approach to photography comes from smart phones–which feature powerful computers and increasingly capable imaging equipment.
“If other people in the mobile space start to experiment with these ideas, and users find that useful or cool, we will see similar apps in the biggest mobile app stores,” says Levoy. “That will put pressure on the camera industry to open up to allow similar innovation using their platforms.”
The images captured using computational photography can be s
tunning. For example, a camera can rapidly shoot a series of images while varying its focus, before combining them to make a single image in which objects at any distance appear sharp.
The software released for the N900 consists of one version of the Frankencamera software platform and a handful of apps built for it. One app lets the camera shoot three images of a scene with different exposures to capture both light and dark parts, resulting in a “high dynamic range” (HDR) image. Another guides a user to capture a series of overlapping images across a scene, and varies the exposur
e in adjacent photos so that a composite image can be stitched together in HDR. A third app, called Lucky Imaging, ensures sharp results in low light by constantly shooting images but only storing those judged by the software to be sharp enough.
An iPhone app called Pro HDR already makes it possible to take HDR images on the iPhone, although the app only combines two images. Another app, You Gotta See This, uses the gyroscope in the new iPhone 4 to create a panorama when a person scans their phone across a scene.
“Camera manufacturers used to ignore phones because they coul
d say the image quality was too poor to worry about,” Worthington says. Now that’s changed. “Today it is smart cameras versus dumb cameras,” he says.
Levoy hopes phone vendors will adopt some of the ideas in the Frankencamera platform to enable even more powerful camera apps. But fully embracing computational photography will require more than just software tweaks to cell phones. “To really enable computational photography on smart phones, there may need to be a virtuous cycle where vendors go to their hardware suppliers and ask for more flexible components,” Levoy says.