CVPR 2024 Papers

Unlike color photography images which are consistently encoded into RGB channels biological images encompass various modalities where the type of microscopy and the meaning of each channel varies with each experiment. Importantly the number of channels can range from one to a dozen and their correlation is often comparatively much lower than RGB as each of them brings specific information content. This aspect is largely overlooked by methods designed out of the bioimage field and current solutions mostly focus on intra-channel spatial attention often ignoring the relationship between channels yet crucial in most biological applications. Importantly the variable channel type and count prevent the projection of several experiments to a unified representation for large scale pre-training. In this study we propose ChAda-ViT a novel Channel Adaptive Vision Transformer architecture employing an Inter-Channel Attention mechanism on images with an arbitrary number order and type of channels. We also introduce IDRCell100k a bioimage dataset with a rich set of 79 experiments covering 7 microscope modalities with a multitude of channel types and channel counts varying from 1 to 10 per experiment. Our proposed architecture trained in a self-supervised manner outperforms existing approaches in several biologically relevant downstream tasks. Additionally it can be used to bridge the gap for the first time between assays with different microscopes channel numbers or types by embedding various image and experimental modalities into a unified biological image representation. The latter should facilitate interdisciplinary studies and pave the way for better adoption of deep learning in biological image-based analyses.

Building accurate maps is a key building block to enable reliable localization planning and navigation of autonomous vehicles. We propose a novel approach for building accurate 3D maps of dynamic environments utilizing a sequence of LiDAR scans. To this end we propose encoding the 4D scene into a novel spatio-temporal implicit neural map representation by fitting a time-dependent truncated signed distance function to each point. Using our representation we can extract the static map by filtering the dynamic parts. Our neural representation is based on sparse feature grids a globally shared decoder and time-dependent basis functions which can be jointly optimized in an unsupervised fashion. To learn this representation from a sequence of LiDAR scans we design a simple yet efficient loss function to supervise the map optimization in a piecewise way. We evaluate our approach on various scenes containing moving objects in terms of the reconstruction quality of static maps and the segmentation of dynamic point clouds. The experimental results demonstrate that our method is capable of removing the dynamic part of the input point clouds while reconstructing accurate and complete large-scale 3D maps outperforming several state-of-the-art methods for static map generation and scene reconstruction.