6533b833fe1ef96bd129b4b5

RESEARCH PRODUCT

Compréhension de scènes urbaines basée sur la polarisation

Marc Blanchon

subject

Deep LearningSegmentation[INFO.INFO-TS]Computer Science [cs]/Signal and Image Processing[INFO.INFO-TS] Computer Science [cs]/Signal and Image ProcessingComputer VisionVision par ordinateurPolarimetryScene understandingDepth estimationEstimation de profondeurPolarimétrieCompréhension de scène

description

Humans possess an innate ability to interpret scenes under any condition. Computer Vision tends to mimic these capabilities by implementing intelligent algorithms to address complex understanding problems. In this regard, we are interested in understanding outdoor urban scenes in various weather conditions. This thesis specifically addresses the problems arising from the presence of specularity in the scenes. To this end, we aim to take advantage of polarization indices to define such surfaces in addition to traditional objects. In terms of understanding, we aim to introduce polarization to the fields of computer vision and deep learning.This thesis focuses on the following underlying challenges. First, the estimation of a semantic segmentation at the pixel level is investigated. We exploit polarization cues to define constraints upstream of the convolutional network and thus inject specularity understanding into the model. As DCNNs are data intensive, we propose the acquisition of a multimodal dataset allowing the comparison of the proposed method with RGB-centric methods. Moreover, to counteract the massive need for data, we establish a procedure to augment the polarimetric informations while maintaining the physical integrity of the information.In a second line of research, we address the problem of depth map estimation with a monocular image. Since the algorithms require a colorimetric information, we adapt the processes to an alternative type of imagery. This results in novel regularization terms that allow to accurately infer a depth map from a unique polarimetric image using deep learning. Constrained by the greedy aspect of DL, we build a loss function in accordance with the self-supervision principle. In this manner, we demonstrate the possibility to regularize the depth inference process using terms constraining the normals by relying on polarization. This approach allows us to reconstruct more accurately surfaces observing specular behavior or transparency phenomena.Ultimately, our two lines of research show advances towards a more conventional use of polarization in modern computer vision.

https://tel.archives-ouvertes.fr/tel-03469970/document