Abstract

The target of the present invention is to provide an automatic high speed, low-cost, multi-mode three-dimensional(3D) surface profile measurement method. This method exploits the projected energy with a known spatially distributed wavelength spectrum on the surface of objects in the scene. The unique wavelength is encoded with geometry information of a unique projection ray of the radiation energy in 3D space. This wavelength of the projected energy is detected by a 2D image sensor array that is able to uniquely distinguish the wavelength of the radiation energy at the points of interest on the scene. The projection geometry information is recovered by using a color match scheme and the range values associated with every pixel of the 2D image sensor will be calculated through a straightforward triangulation algorithm. Full frames of 3D range images can then be obtained directly at the frame acquisition rate of the 2D image sensor array. The color ranging method eliminates the time consuming corresponding feature finding problem of normal binocular 3D imaging systems. Therefore, it is suitable for high speed, real-time measurement automation. Since there are no mechanical moving parts in our color ranging method, the mechanical design can be very simple and reliable. All components in this system are available off-the-shelf which leads to low cost. With the active light source being turned on or off, the same color camera can provide normal intensity images as well as 3D range data. This multi-mode capability greatly simplifies the problems of multiple sensor integration and sensor data fusion. Depending on the applications, the scope of the color spectrum of the energy projector can be selected from UV, visible, or IR light region. The Color Ranging method is not based on a laser therefore there is no "eyes safe" problem. This is certainly a desirable feature enable this system to be used for other commercial applications, such as medical applications like the facial plastic reconstruction surgery evaluation.