The Leap is a small USB device designed for desktop and laptop computers. It detects and tracks hands, fingers, or anything else that is about the shape of a finger. Contrary to the Microsoft Kinect, it was created to work at very close range. The precision is great and the latency is low.
The Leap needs to be placed underneath the screen to track fingers when they are pointed toward it. It’s field of view is quite large, and looks like an inverted pyramid is about 60-70 centimeters tall. The stereoscopic cameras use wide angle lenses, which helps to see on the sides. The picture underneath shows an approximation of what the leap can track.
So far the Leap can only send simple informations : the position of the hand, of each finger and their direction. This last bit of information helps to detect gestures and small movements.
Few informations are known about the way the Leap works. It is however pretty reliable and is not very sensitive to sunlight, contrary to the kinect. This is probably because of the way the technology works. The Kinect uses what is called Structured Light, which means that it sends a structured cloud of points of infra-red light in space and detects the way it is reflected on surfaces. The Leap, however, emits infra-red light and compares what each of the two infra-red cameras detects. It is basically the same as the human eye in this respect. The following picture shows infra-red light that the leap is emitting with 3 LEDs, as seen from the Kinect infra-red camera.
The Leap will be sold for about US$ 80 in the US, and shortly after in the rest of the world. It will also be bundled with some laptops and desktop by Asus, so it is nearly certain that a few millions will be dispatched before the end of the year. Use case however are still in their infancy. A lot of ways the Leap can be used have not be thought of yet. By sending a few thousands devices to developers, Leap Motion hopes to see new apps designed to make use of its possibilities. They recently announced their Application Store, to provide a platform dedicated to Leap software.