MiPa: Mixed Patch Infrared-Visible Modality Agnostic Object Detection

In this paper, we present a different way to use two modalities, in which either one modality or the other is seen by a single model. This can be useful when adapting an unimodal model to leverage more information while respecting a limited computational budget. This would mean having a single model that is able to deal with any modalities. To describe this, we coined the term anymodal learning. An example of this, is a use case where, surveillance in a room when the lights are off would be much more valuable using an infrared modality while a visible one would provide more discriminative information when lights are on. This work investigates how to efficiently leverage visible and infrared/thermal modalities for transformer-based object detection backbone to create an anymodal architecture. Our work does not create any inference overhead during the testing while exploring an effective way to exploit the two modalities during the training. To accomplish such a task, we introduce the novel anymodal training technique: Mixed Patches (MiPa), in conjunction with a patch-wise domain agnostic module, which is responsible of learning the best way to find a common representation of both modalities. This approach proves to be able to balance modalities by reaching competitive results on individual modality benchmarks with the alternative of using an unimodal architecture on three different visible-infrared object detection datasets. Finally, our proposed method, when used as a regularization for the strongest modality, can beat the performance of multimodal fusion methods while only requiring a single modality during inference. Notably, MiPa became the state-of-the-art on the LLVIP visible/infrared benchmark. Code: https://github.com/heitorrapela/MiPa

Modality Translation for Object Detection Adaptation Without Forgetting Prior Knowledge

A common practice in deep learning consists of training large neural networks on massive datasets to perform accurately for different domains and tasks. While this methodology may work well in numerous application areas, it only applies across modalities due to a larger distribution shift in data captured using different sensors. This paper focuses on the problem of adapting a large object detection model to one or multiple modalities while being efficient. To do so, we propose ModTr as an alternative to the common approach of fine-tuning large models. ModTr consists of adapting the input with a small transformation network trained to minimize the detection loss directly. The original model can therefore work on the translated inputs without any further change or fine-tuning to its parameters. Experimental results on translating from IR to RGB images on two well-known datasets show that this simple ModTr approach provides detectors that can perform comparably or better than the standard fine-tuning without forgetting the original knowledge. This opens the doors to a more flexible and efficient service-based detection pipeline in which, instead of using a different detector for each modality, a unique and unaltered server is constantly running, where multiple modalities with the corresponding translations can query it. Code: https://github.com/heitorrapela/ModTr.