Industrial Engineering Department, Faculty of Engineering and Technology, University of La Laguna, 38200 San Cristóbal de La Laguna, Spain.
IACTEC Medical Technology Group, Instituto de Astrofísica de Canarias (IAC), 38205 San Cristóbal de La Laguna, Spain.
Sensors (Basel). 2021 Mar 24;21(7):2264. doi: 10.3390/s21072264.
This work presents a revision of four different registration methods for thermal infrared and visible images captured by a camera-based prototype for the remote monitoring of diabetic foot. This prototype uses low cost and off-the-shelf available sensors in thermal infrared and visible spectra. Four different methods (Geometric Optical Translation, Homography, Iterative Closest Point, and Affine transform with Gradient Descent) have been implemented and analyzed for the registration of images obtained from both sensors. All four algorithms' performances were evaluated using the Simultaneous Truth and Performance Level Estimation (STAPLE) together with several overlap benchmarks as the Dice coefficient and the Jaccard index. The performance of the four methods has been analyzed with the subject at a fixed focal plane and also in the vicinity of this plane. The four registration algorithms provide suitable results both at the focal plane as well as outside of it within 50 mm margin. The obtained Dice coefficients are greater than 0.950 in all scenarios, well within the margins required for the application at hand. A discussion of the obtained results under different distances is presented along with an evaluation of its robustness under changing conditions.
这项工作对基于相机的糖尿病足远程监测原型所获取的热红外和可见光图像的四种不同配准方法进行了修正。该原型使用热红外和可见光谱中低成本和现成的传感器。为了配准来自两个传感器的图像，实现并分析了四种不同的方法（几何光学平移、单应性、迭代最近点和带梯度下降的仿射变换）。使用同时真实和性能水平估计（STAPLE）以及重叠基准（如骰子系数和杰卡德指数）对所有四种算法的性能进行了评估。在固定焦平面和该平面附近对四种方法的性能进行了分析。四种配准算法在焦平面以及 50 毫米范围内都提供了合适的结果。在所有情况下，获得的骰子系数都大于 0.950，完全满足当前应用所需的容限。本文还讨论了不同距离下的结果，并评估了在变化条件下的鲁棒性。
