Imagine that you take a picture of your child using your cell phone, while out for a walk. When you come home, you might want to store this image on your PC and print a copy using your PC printer. Wouldn’t it be so much easier if you could do all of this just by moving your cell phone in front of your PC screen?

With the new technology, a user can move pictures on the PC screen by simply pointing the cameraphone at the screen and clicking and moving it around (right).  The same method could be used to draw an image, such as that of a house (left). The program also allows users to zoom in and out of photos by moving the phone closer and further away. Since the PC screen’s content is also displayed on the phone’s screen, a user can perform operations from a distance as well

For example, you could look at the ‘My Documents’ folder through the cell-phone camera, and twist the phone momentarily to open that folder. Do the same for the ‘My Pictures’ folder, and then, by moving the phone towards the PC screen, you could transfer all the recently taken images to the PC over a Bluetooth link.

This is now possible, thanks to a new program developed by Nick Pears at the University of York, UK, and his colleagues Patrick Olivier and Dan Jackson at the Newcastle University.

“The basic requirements for this technology are that your phone has got to have a camera on the rear and a wireless connection with the PC, such as Bluetooth,” Pears says.

And of course, you would need to have the program installed on both, your PC as well as your cameraphone.


The camera on the phone looks at the PC screen and extracts some features, such as the corners of windows; their positions are sent from the phone to the PC over the Bluetooth link.

The PC then compares these positions with what it knows that it is displaying on its own screen. Thus, it can calculate precisely what the phone is looking at on its screen. In human terms, it is like knowing where your nose is, but being able to touch it precisely on a point you desire by getting visual feedback from a mirror.

The computer can also calculate the phone’s position and orientation relative to the PC screen. Thus, the phone can be used as a six-degree of freedom ‘flying mouse’, a bit like the Wiimote – the controller for Nintendo’s video game console Wii.

“But it is more than that,” Pears says. “Since you have a cloned part of the PC screen on your cell phone screen, you can interact with the PC screen through the phone.”


Pears recently conducted some tests with random users to see the usability of the technology.

In the tests, users were shown a set of images on the screen, and asked to rearrange them according to a pre-given order. The participants managed it easily.

By depressing a trigger button on the smartphone, the user was able to manipulate the targeted image. The images could be moved and rotated by mimicking the action on the phone, parallel to the display

Users could also zoom in by moving the phone closer to the screen, and zoom out by moving it away.

In another test, users drew the basic outline of a house by clicking and moving the mouse around like a pointer – all of this using the Microsoft Paint software.

But the applications of this technology aren’t for just interacting with PCs.

“This starts to get really exciting, when you realise that large public displays are just PCs with a large screen,” Pears says.

For example, imagine the future where billboard advertisements are computerised – something like a Web page. You may want the details of a property advertised on a screen in an estate agent’s window, when the estate agent is closed. Obviously, you cannot interact directly with the screen, as it is behind a pane of glass.

It would, however, be possible to interact via your phone using this new invention, because you have a cloned copy of part of the advertising screen on your phone screen.

“By simply tapping a particular property icon, viewed on your touch-sensitive phone screen, such a tap is echoed through Bluetooth to the appropriate point on the estate agent’s screen, and so any action on that property data can be triggered,” Pears says.

“You could open the full advertising screen out to show more images of the property or sending the property details to your phone via Bluetooth or sending details of the property to your email account,” he adds.

The number of ways this technology could be used are only as limited as your imagination, he concludes.