7,326 research outputs found
DeepOrientation: convolutional neural network for fringe pattern orientation map estimation
Fringe pattern based measurement techniques are the state-of-the-art in
full-field optical metrology. They are crucial both in macroscale, e.g., fringe
projection profilometry, and microscale, e.g., label-free quantitative phase
microscopy. Accurate estimation of the local fringe orientation map can
significantly facilitate the measurement process on various ways, e.g., fringe
filtering (denoising), fringe pattern boundary padding, fringe skeletoning
(contouring/following/tracking), local fringe spatial frequency (fringe period)
estimation and fringe pattern phase demodulation. Considering all of that the
accurate, robust and preferably automatic estimation of local fringe
orientation map is of high importance. In this paper we propose novel numerical
solution for local fringe orientation map estimation based on convolutional
neural network and deep learning called DeepOrientation. Numerical simulations
and experimental results corroborate the effectiveness of the proposed
DeepOrientation comparing it with the representative of the classical approach
to orientation estimation called combined plane fitting/gradient method. The
example proving the effectiveness of DeepOrientation in fringe pattern
analysis, which we present in this paper is the application of DeepOrientation
for guiding the phase demodulation process in Hilbert spiral transform. In
particular, living HeLa cells quantitative phase imaging outcomes verify the
method as an important asset in label-free microscopy
Augmentation-aware Self-supervised Learning with Guided Projector
Self-supervised learning (SSL) is a powerful technique for learning robust
representations from unlabeled data. By learning to remain invariant to applied
data augmentations, methods such as SimCLR and MoCo are able to reach quality
on par with supervised approaches. However, this invariance may be harmful to
solving some downstream tasks which depend on traits affected by augmentations
used during pretraining, such as color. In this paper, we propose to foster
sensitivity to such characteristics in the representation space by modifying
the projector network, a common component of self-supervised architectures.
Specifically, we supplement the projector with information about augmentations
applied to images. In order for the projector to take advantage of this
auxiliary guidance when solving the SSL task, the feature extractor learns to
preserve the augmentation information in its representations. Our approach,
coined Conditional Augmentation-aware Selfsupervised Learning (CASSLE), is
directly applicable to typical joint-embedding SSL methods regardless of their
objective functions. Moreover, it does not require major changes in the network
architecture or prior knowledge of downstream tasks. In addition to an analysis
of sensitivity towards different data augmentations, we conduct a series of
experiments, which show that CASSLE improves over various SSL methods, reaching
state-of-the-art performance in multiple downstream tasks.Comment: Prepint under review. Code: https://github.com/gmum/CASSL
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