Researchers in Japan are developing a gadget that could enable people to hold a three-dimensional image of someone in the palm of their hand.

They hope the gCubik, which is still at the prototype stage, will later be developed to move in real time and appear to speak.

"The ultimate image we have in mind is having a small person in your palm," said Shunsuke Yoshida, one of the researchers involved in the study at Japan's National Institute of Information and Communications Technology.

"Suppose you have a picture of your girlfriend smiling on your desk. She could be smiling as a 3D image in a cube," he told AFP at a recent gathering of imaging researchers here.

Grandparents could use the device -- which comes in a 10 centimetre (3.9 inches) cube -- to see a 3D image of their grandchild living far away, while business people could view a prototype product from afar and school teachers could use it in science classes, he said.

At the moment the device has a still image but efforts are underway to make it move in real time, Yoshida said.

The panels have many tiny lenses on liquid crystal displays. Unlike conventional 3D displays, which are viewed only from the front, the gCubik can be seen from three sides, giving different images from various angles. And unlike conventional 3D users will not need glasses to see the benefit.

Yoshida said the team hopes to put the technology to practical use within about three years by improving picture quality, getting rid of cords now attached to the cube and allowing viewing from all six sides of the box.

The team also wants to give vocal sounds to the 3D image in the future, making it appear as if the person in the cube is speaking.