基于二维医学影像推算三维人体姿态

Estimation of Three-Dimensional Human Posture Based on Two-Dimensional Medical Images

摘要: 针对三维人体姿态估计模型复杂，计算量偏大的问题，提出一种基于二维医学影像推算三维人体姿态的方法。在特定姿态下采集人体医学影像并进行二维影像姿态估计，得到人体各个骨骼的医学影像的长度信息。再在人体位置不发生改变的情况下，对任意姿态的人体采集图像并进行二维医学影像的人体姿态估计，得到骨骼在与相机透镜主光轴垂直平面上的投影的影像的近似长度，反推骨骼与该平面的夹角，最后从投影的影像位置反推骨骼的三维空间朝向。最后将得到的各个骨骼的空间朝向组合在一起，便得到了三维人体医学影像。使用此方法只需要对医学图像进行二维人体姿态估计，再加上一些三角函数、反三角函数的计算就可以从二维医学影像去推算三维人体姿态。与ICCV 2019中代表当今最高水平(State of the Art, SOTA)的三维人体姿态模型的方法相比，大大减少了计算量。

Abstract: Considering the complexity of 3-D human pose estimation model and the computation of its training and very high inference, the estimation of three-dimensional human posture based on two-dimensional medical images is proposed. By capturing a human’s medical image with a certain pose and doing 2-D human pose estimation on it, the result can be used to get the bones’ medical image length. And then acquiring an image of a human body of an arbitrary posture and estimating the human body posture of a two-dimensional medical image without changing the human body position. As to every bone, an approximate length of the image of the bone’s projection on a plane that is perpendicular to the main axis of the camera lens can be got. Furthermore, with this approximate length of the medical image, the angle between the bone and the plane can be inferred. Finally, the spatial orientation of the bone can be inferred with this angle and that image position. With the orientations of bones of human skeleton, a 3-D human pose can be composed. Using our method, through a 2-D human medical image pose estimation, some trigonometric calculation and some inverse trigonometric calculation, a 3-d human pose estimation can be figured out. Compared with the three-dimensional human posture model in ICCV 2019, which represents the highest state of the art (SOTA), the calculation amount is greatly reduced.