Research On 3D Reconstruction Technology Based On Colored Surface Structured Light

Three-dimensional measurement technology has a wide application prospect in the fields of cultural relic restoration,auxiliary medical treatment,reverse engineering and instrument manufacturing.In 3D measurement technology,3D measurement technology based on coded structured light is widely used due to its high precision,low cost,non-contact with other things,good scalability and other advantages.This paper focuses on the study of the codec of color plane structural light patterns,and designs a color stripe structural light measurement scheme based on DB(De Bruijn)sequence,which mainly includes the following contents:(1)In the process of projection,color structural light patterns tend to be crosstalk between adjacent colors,which leads to the difficulty of decoding and the decrease off measurement accuracy.To solve this problem,this paper designs a color scheme of structured light stripes based on two constraints,namely RGB color space distance value and color ring contrasting color.The color scheme of structured light fringes selected by this scheme is characterized by large color difference and ease of differentiation,which can effectively reduce the probability of crosstalk and boundary confusion between adjacent structured light.At the same time,two encoding methods of constrained DB sequence structured light and inserted DB sequence structured light are presented based on this method,which can meet the requirements of different resolution of coding patterns in different measurement scenarios.(2)The projection of the color structural light pattern is easily affected by the environment and equipment,resulting in noise and color attenuation phenomenon,which can not accurately determine the color of the code,leading to the failure of decoding.To solve this problem,a new color enhancement method is proposed in this paper.Firstly,the classical median filter algorithm is improved,which can quickly and effectively remove the noise in the stripe pattern of structural light.Then the color in the pattern of structural light is calibrated to obtain the projection attenuation relation of each color,so as to accurately recover the color information of structural light,avoid color misjudgment,and improve the decoding accuracy.(3)Due to the influence of ambient light and equipment,the color fringe structure light will be confused at the fringe boundary,and the fringe boundary cannot be accurately obtained,resulting in the decrease of measurement accuracy.To solve this problem,a bar window boundary detector is designed in this paper.The effective pixel colors on the left and right sides of the pixels that have boundary confusion are statistically compared,and then the real color values of the pixels that have boundary confusion are judged.This method can accurately judge the fringe boundary and improve the measurement accuracy.The codec scheme of color structural light designed in this paper is adopted to measure different shapes of plane,regular geometry and non-regular geometry.The experimental results show that the average deviation error of plane fitting point cloud is approximately 0.94mm,and the maximum deviation error is within 3.11mm range.The measurement and reconstruction results of regular geometry and non-regular geometry can accurately reflect the morphological characteristics of geometry and verify the feasibility and effectiveness of the system designed in this paper.