3D Reconstruction System Based On Structured Light

In the last decade,3D shape acquisition has received more and more consider-able research interests. Since the moment when the concept of3D reconstruction was proposed, researchers have developed some groups of techniques to achieve3D shape acquisition, some important methods include and structured light, stereo vision and TOF(Time Of Flight). Among those methods, one of the main advantages of structured light based techniques is that it requires less and easier image processing, meanwhile, it can derive high accuracy in the3D reconstruction result. Based on the math of triangle principle, structured light based techniques take three steps to fulfill final result. The first step is to project some designed coding patterns onto the surface of the scanned objects. After that, a camera (or more) is controlled to capture the scene and send the pictures to computer for further processing. In the second step, algorithms detect the coding patterns in the captured image and establish the correspondence with projected patterns. In the final step,3D coordinates of the object surface are calculated from the correspondence established in the second step within the calibrated triangle model.In the review of the development history of structured light techniques, the first appeared techniques are the time-multiplexing techniques, which are also called multi-shots techniques because multi patterns are projected onto the surface and multi images are taken. Actually there are both advantages and disadvantages using this method. Ad-vantages include high accuracy and resolution and the disadvantage is that the scanning speed is slow. After that, one-shot structured light system is developed to achieve high resolution within a short time. In one-shot structured light system, there are three key processes which would effect final reconstruction result, which includes the choose of projected patterns, detection of pattern in captured image and the algorithms applied to establishment of correspondence between captured and projected patterns. Recently, more and more efforts have been made in order to generate higher quality result, which makes this method widely used in industry design and cultural heritage protection.In this paper, we have build a structure light system and this system uses two methods:De Bruijn code based colored stripe and Gay code as structure light, which belongs to one-shot structured light technique and time-multiplexing technique. To achieve a better reconstruction result using colored stripes, we propose an adaptive color calibration method, and a Discrete Trend Transform (DTT) algorithm to detec-t patterns. And we proposed a method to detect the edge of Gray code structured light edge. In this system, dark laboratory environments is not needed to derive high-resolution3D point cloud.