Gaussian Constrained Diffeomorphic Deformation Network for Panoramic Semantic Segmentation

Panoramic semantic segmentation has garnered increasing attention due to its ability to provide comprehensive environmental perception. However, it requires a large number of annotated panoramic images to achieve satisfactory performance, which is costly. Recently, Domain Adaptation for Panoramic Semantic Segmentation (DA4PASS) has been proposed to reduce the reliance on annotated data by transferring segmentation models trained on annotated pinhole images to unlabelled panoramic images. Previous DA4PASS methods mainly focus on aligning features between pinhole and panoramic images, overlooking the unique appearance characteristics of panoramic images, particularly object distortion. To address the appearance discrepancies between pinhole and panoramic images, we propose Gaussian Constrained Diffeomorphic Deformation Network (GCDDN), which applies a panoramic deformation transformation obtained by Gaussian kernels to the annotated pinhole images. Specifically, GCDDN predicts multiple Gaussian kernels and performs first-order horizontal/vertical differences to obtain a naturally smooth and reversible panoramic deformation field, which is diffeomorphic. Due to its universality, GCDDN can be integrated into any domain adaptation (DA) method. Extensive experimental results demonstrate that integrating GCDDN leads to substantial improvements in both DA methods for pinhole images and those specifically designed for panoramic images, with a maximum gain of 1.80% in outdoor scenarios. Code is available at https://github.com/jingjiang02/GCDDN.