水下多通道真彩色三维重建与颜色还原方法研究

发布时间：2019-06-17 11:46

【摘要】：水下图像探测是海洋探测的重要方式，近年来随着光电成像技术与三维测距技术的迅速发展，传统的水下图像探测方法逐渐向三维方向发展，随着各国对海洋资源开发利用的重视，水下三维重建方法逐渐成为海洋探测领域的研究热点。线结构光扫描法是一种常用的水下三维重建方法，具有较高的重建分辨率，光束能量较集中，可以减少水下后向散射光的影响，具有较远的探测距离，但传统的线结构光扫描法无法获取目标的彩色信息。本文提出一种多通道结构光扫描方法进行水下目标的真彩色三维重建，改进了线结构光扫描系统，利用三基色激光作为主动光源，以CCD相机作为图像接收器，，建立了水下多通道真彩色三维扫描实验系统，分通道获取三基色彩色信息，实验结果表明此方法可在高分辨率三维重建的基础上同时复原目标的真彩色信息。基于线结构光扫描法，本文提出了一种寻址最近标定点的三维重建算法，建立了扫描图像的二维像素坐标系与真实空间的三维世界坐标系的映射关系；采用寻址最近标定点的方法，搜索距数据点最近的标定点，再根据已建立的坐标系映射关系计算三维坐标。此方法不同于传统的结构光扫描三维重建方法，不涉及三角几何关系的计算，高效易行，易于快速、实时地获取并重建三维信息。为还原水下图像的真彩色信息，提出了一种基于感光曲线拟合的三基色校正方法，建立三基色记录值与标准值之间的映射关系，以此作为颜色还原的校正根据。在以上三基色校正方法的基础上，进一步提出基于CCD相机的水下衰减系数测量方法和衰减颜色补偿方法。为证明以上方法的有效性进行了系统的实验，扫描并重建了水下三维场景，实现了毫米量级三维重建，并成功再现了水下被测物体的真实彩色纹理图像信息；针对不同深度的水下颜色衰减，测量衰减系数，再分别利用两种方法：功率前补偿法、图像后补偿法，进行了水下颜色补偿实验，均实现了较为真实准确的颜色再现。本文提出的方法和系统作为一种水下三维成像方式，可以应用于水下地形环境的探测、水下三维地形图的绘制、水下目标的三维重建、辅助水底资源勘探等方面，具有一定的应用潜力和应用价值。
[Abstract]:Underwater image detection is an important way of ocean detection. In recent years, with the rapid development of optoelectronic imaging technology and three-dimensional ranging technology, the traditional underwater image detection methods are gradually developing in the three-dimensional direction. With the attention paid by countries to the development and utilization of marine resources, underwater three-dimensional reconstruction methods have gradually become a research focus in the field of ocean exploration. Line structured light scanning method is a common underwater 3D reconstruction method, which has high reconstruction resolution and concentrated beam energy. It can reduce the influence of underwater backward scattering light and has a long detection distance, but the traditional line structured light scanning method can not obtain the color information of the target. In this paper, a multi-channel structured light scanning method is proposed to reconstruct the true color 3D of underwater targets. The line structured light scanning system is improved. Using the trichromatic laser as the active light source and the CCD camera as the image receiver, the underwater multi-channel true color 3D scanning experimental system is established, and the trichromatic color information is obtained by channels. The experimental results show that this method can restore the true color information of the target at the same time on the basis of high resolution 3D reconstruction. Based on the line structured light scanning method, a 3D reconstruction algorithm for addressing the nearest calibration point is proposed in this paper, and the mapping relationship between the two-dimensional pixel coordinate system of the scanned image and the three-dimensional world coordinate system in the real space is established, and the nearest calibration point to the data point is searched by the method of addressing the nearest calibration point, and then the three-dimensional coordinates are calculated according to the established coordinate system mapping relationship. This method is different from the traditional structured light scanning 3D reconstruction method. It does not involve the calculation of triangular geometric relations. It is efficient, easy to obtain and reconstruct 3D information in real time. In order to restore the true color information of underwater image, a three-primary color correction method based on photosensitive curve fitting is proposed, and the mapping relationship between the three primary color recording value and the standard value is established, which can be used as the correction basis for color reduction. On the basis of the above three primary color correction methods, the underwater attenuation coefficient measurement method and attenuation color compensation method based on CCD camera are further proposed. In order to prove the effectiveness of the above method, the underwater 3D scene is scanned and reconstructed, the millimeter order 3D reconstruction is realized, and the real color texture image information of the underwater measured object is successfully reproduced. Aiming at the underwater color attenuation of different depths and measuring the attenuation coefficient, two methods, pre-power compensation method and image post-compensation method, are used to carry out the underwater color compensation experiment, which realizes the more real and accurate color reproduction. As a kind of underwater 3D imaging method, the method and system proposed in this paper can be applied to the detection of underwater topographic environment, the drawing of underwater 3D topographic map, the 3D reconstruction of underwater target, the auxiliary underwater resource exploration and so on, and have certain application potential and application value.
【学位授予单位】：中国海洋大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：P714;P715.5

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