Laparoscopic stereo matching using 3-Dimensional Fourier transform with full multi-scale features

3-Dimensional (3D) reconstruction of laparoscopic surgical scenes is a key task for future surgical navigation and automated robotic minimally invasive surgery. Binocular laparoscopy with stereo matching enables 3D reconstruction. Stereo matching models used for natural images such as autopilot tend to be less suitable for laparoscopic environments due to the constraints of small samples of laparoscopic images, complex textures, and uneven illumination. In addition, current stereo matching modules use 3D convolutions and transformers in the spatial domain as the base module, which is limited by the ability to learn in the spatial domain. In this paper, we propose a model for laparoscopic stereo matching using 3D Fourier Transform combined with Full Multi-scale Features (FT-FMF Net). Specifically, the proposed Full Multi-scale Fusion Module (FMFM) is able to fuse the full multi-scale feature information from the feature extractor into the stereo matching block, which densely learns the feature information with parallax and FMFM fusion information in the frequency domain using the proposed Dense Fourier Transform Module (DFTM). We validated the proposed method in both the laparoscopic dataset (SCARED) and the endoscopic dataset (SERV-CT). In comparison with other popular and advanced deep learning models available at present, FT-FMF Net achieves the most advanced stereo matching performance available. In the SCARED and SERV-CT public datasets, the End-Point-Error (EPE) was 0.7265 and 2.3119, and the Root Mean Square Error Depth (RMSE Depth) was 4.00 mm and 3.69 mm, respectively. In addition, the inference time is only 0.17s. Our project code is available on https://github.com/wurenkai/FT-FMF.