Three-dimensional images are incredibly useful for calculating and recording the measurements of objects quickly and efficiently. However, conventional imaging devices weigh around 4 to 5 kg and measure roughly 50 cm long, which makes them impractical for applications outside the laboratory.Researchers at Fraunhofer Institute for Applied Optics and Precision Engineering may have solved this problem, however. They have designed a cordless 3-D sensor that weighs about 1 kg, is no larger than a shoebox, draws its power from batteries and sends its data to the computer via a wireless local area network. A lightweight, cordless 3-D sensor enables the imaging of objects such as tyre tracks. Image courtesy of Fraunhofer Institute for Applied Optics and Precision Engineering.The device, named the Kolibri Cordless, comprises two cameras and a projector that casts a pattern of stripes onto the subject. Deformations in the stripes help measure the object.The projector uses LEDs, rather than the traditional halogen lamps, as its projector light. This enabled the investigators to make the instrument more compact, although the light produced by the LEDs must be collected with micro-optics such that, when it affects the lens, it is bright enough to yield accurate measurements.The compact, cordless imager has many real-world applications in fields that include forensics. For example, the device could replace the plaster casts made of tyre tracks at crime scenes. Officers would simply use the imager as they would a camera to take a picture of the track and then upload the image to a laptop.