# MixImages: An Urban Perception AI Method Based on Polarization Multimodalities

## TL;DR

This paper introduces MixImages, a new AI method that uses polarization data with RGB images to improve urban scene perception accuracy.

## Contribution

The novel MixImages model combines polarization multimodalities with RGB data for better urban perception performance.

## Key findings

- MixImages achieved a 3.43% accuracy improvement over RGB-only models in unimodal benchmarks.
- It showed a 4.29% performance gain in multimodal benchmarks using polarization data.
- Different polarization type combinations were tested for their impact on segmentation accuracy.

## Abstract

Intelligent urban perception is one of the hot topics. Most previous urban perception models based on semantic segmentation mainly used RGB images as unimodal inputs. However, in natural urban scenes, the interplay of light and shadow often leads to confused RGB features, which diminish the model’s perception ability. Multimodal polarization data encompass information dimensions beyond RGB, which can enhance the representation of shadow regions, serving as additional data for assistance. Additionally, in recent years, transformers have achieved outstanding performance in visual tasks, and their large, effective receptive field can provide more discriminative cues for shadow regions. For these reasons, this study proposes a novel semantic segmentation model called MixImages, which can combine polarization data for pixel-level perception. We conducted comprehensive experiments on a polarization dataset of urban scenes. The results showed that the proposed MixImages can achieve an accuracy advantage of 3.43% over the control group model using only RGB images in the unimodal benchmark while gaining a performance improvement of 4.29% in the multimodal benchmark. Additionally, to provide a reference for specific downstream tasks, we also tested the impact of different combinations of polarization types on the overall segmentation accuracy. The proposed MixImages can be a new option for conducting urban scene perception tasks.