13 research outputs found
Binarized Spectral Compressive Imaging
Existing deep learning models for hyperspectral image (HSI) reconstruction
achieve good performance but require powerful hardwares with enormous memory
and computational resources. Consequently, these methods can hardly be deployed
on resource-limited mobile devices. In this paper, we propose a novel method,
Binarized Spectral-Redistribution Network (BiSRNet), for efficient and
practical HSI restoration from compressed measurement in snapshot compressive
imaging (SCI) systems. Firstly, we redesign a compact and easy-to-deploy base
model to be binarized. Then we present the basic unit, Binarized
Spectral-Redistribution Convolution (BiSR-Conv). BiSR-Conv can adaptively
redistribute the HSI representations before binarizing activation and uses a
scalable hyperbolic tangent function to closer approximate the Sign function in
backpropagation. Based on our BiSR-Conv, we customize four binarized
convolutional modules to address the dimension mismatch and propagate
full-precision information throughout the whole network. Finally, our BiSRNet
is derived by using the proposed techniques to binarize the base model.
Comprehensive quantitative and qualitative experiments manifest that our
proposed BiSRNet outperforms state-of-the-art binarization methods and achieves
comparable performance with full-precision algorithms. Code and models are
publicly available at https://github.com/caiyuanhao1998/BiSCI and
https://github.com/caiyuanhao1998/MSTComment: NeurIPS 2023; The first work to study binarized spectral compressive
imaging reconstruction proble
Generalizing Deep Learning Methods for Particle Tracing Using Transfer Learning
Particle tracing is a very important method for scientific visualization of vector fields, but it is computationally expensive. Deep learning can be used to speed up particle tracing, but existing deep learning models are domain-specific. In this work, we present a methodology to generalize the use of deep learning for particle tracing using transfer learning. We demonstrate the performance of our approach through a series of experimental studies that address the most common simulation design scenarios: varying time span, Reynolds number, and problem geometry. The results show that our methodology can be effectively used to generalize and accelerate the training and practical use of deep learning models for visualization of unsteady flows
Deep learning in remote sensing: a review
Standing at the paradigm shift towards data-intensive science, machine
learning techniques are becoming increasingly important. In particular, as a
major breakthrough in the field, deep learning has proven as an extremely
powerful tool in many fields. Shall we embrace deep learning as the key to all?
Or, should we resist a 'black-box' solution? There are controversial opinions
in the remote sensing community. In this article, we analyze the challenges of
using deep learning for remote sensing data analysis, review the recent
advances, and provide resources to make deep learning in remote sensing
ridiculously simple to start with. More importantly, we advocate remote sensing
scientists to bring their expertise into deep learning, and use it as an
implicit general model to tackle unprecedented large-scale influential
challenges, such as climate change and urbanization.Comment: Accepted for publication IEEE Geoscience and Remote Sensing Magazin
Deep Learning Meets Hyperspectral Image Analysis: A Multidisciplinary Review
Modern hyperspectral imaging systems produce huge datasets potentially conveying a great abundance of information; such a resource, however, poses many challenges in the analysis and interpretation of these data. Deep learning approaches certainly offer a great variety of opportunities for solving classical imaging tasks and also for approaching new stimulating problems in the spatial–spectral domain. This is fundamental in the driving sector of Remote Sensing where hyperspectral technology was born and has mostly developed, but it is perhaps even more true in the multitude of current and evolving application sectors that involve these imaging technologies. The present review develops on two fronts: on the one hand, it is aimed at domain professionals who want to have an updated overview on how hyperspectral acquisition techniques can combine with deep learning architectures to solve specific tasks in different application fields. On the other hand, we want to target the machine learning and computer vision experts by giving them a picture of how deep learning technologies are applied to hyperspectral data from a multidisciplinary perspective. The presence of these two viewpoints and the inclusion of application fields other than Remote Sensing are the original contributions of this review, which also highlights some potentialities and critical issues related to the observed development trends
Quantitative Mapping of Soil Property Based on Laboratory and Airborne Hyperspectral Data Using Machine Learning
Soil visible and near-infrared spectroscopy provides a non-destructive, rapid and low-cost approach to quantify various soil physical and chemical properties based on their reflectance in the spectral range of 400–2500 nm. With an increasing number of large-scale soil spectral libraries established across the world and new space-borne hyperspectral sensors, there is a need to explore methods to extract informative features from reflectance spectra and produce accurate soil spectroscopic models using machine learning.
Features generated from regional or large-scale soil spectral data play a key role in the quantitative spectroscopic model for soil properties. The Land Use/Land Cover Area Frame Survey (LUCAS) soil library was used to explore PLS-derived components and fractal features generated from soil spectra in this study. The gradient-boosting method performed well when coupled with extracted features on the estimation of several soil properties. Transfer learning based on convolutional neural networks (CNNs) was proposed to make the model developed from laboratory data transferable for airborne hyperspectral data. The soil clay map was successfully derived using HyMap imagery and the fine-tuned CNN model developed from LUCAS mineral soils, as deep learning has the potential to learn transferable features that generalise from the source domain to target domain. The external environmental factors like the presence of vegetation restrain the application of imaging spectroscopy. The reflectance data can be transformed into a vegetation suppressed domain with a force invariance approach, the performance of which was evaluated in an agricultural area using CASI airborne hyperspectral data. However, the relationship between vegetation and acquired spectra is complicated, and more efforts should put on removing the effects of external factors to make the model transferable from one sensor to another.:Abstract I
Kurzfassung III
Table of Contents V
List of Figures IX
List of Tables XIII
List of Abbreviations XV
1 Introduction 1
1.1 Motivation 1
1.2 Soil spectra from different platforms 2
1.3 Soil property quantification using spectral data 4
1.4 Feature representation of soil spectra 5
1.5 Objectives 6
1.6 Thesis structure 7
2 Combining Partial Least Squares and the Gradient-Boosting Method for Soil Property Retrieval Using Visible Near-Infrared Shortwave Infrared Spectra 9
2.1 Abstract 10
2.2 Introduction 10
2.3 Materials and methods 13
2.3.1 The LUCAS soil spectral library 13
2.3.2 Partial least squares algorithm 15
2.3.3 Gradient-Boosted Decision Trees 15
2.3.4 Calculation of relative variable importance 16
2.3.5 Assessment 17
2.4 Results 17
2.4.1 Overview of the spectral measurement 17
2.4.2 Results of PLS regression for the estimation of soil properties 19
2.4.3 Results of PLS-GBDT for the estimation of soil properties 21
2.4.4 Relative important variables derived from PLS regression and the gradient-boosting method 24
2.5 Discussion 28
2.5.1 Dimension reduction for high-dimensional soil spectra 28
2.5.2 GBDT for quantitative soil spectroscopic modelling 29
2.6 Conclusions 30
3 Quantitative Retrieval of Organic Soil Properties from Visible Near-Infrared Shortwave Infrared Spectroscopy Using Fractal-Based Feature Extraction 31
3.1 Abstract 32
3.2 Introduction 32
3.3 Materials and Methods 35
3.3.1 The LUCAS topsoil dataset 35
3.3.2 Fractal feature extraction method 37
3.3.3 Gradient-boosting regression model 37
3.3.4 Evaluation 41
3.4 Results 42
3.4.1 Fractal features for soil spectroscopy 42
3.4.2 Effects of different step and window size on extracted fractal features 45
3.4.3 Modelling soil properties with fractal features 47
3.4.3 Comparison with PLS regression 49
3.5 Discussion 51
3.5.1 The importance of fractal dimension for soil spectra 51
3.5.2 Modelling soil properties with fractal features 52
3.6 Conclusions 53
4 Transfer Learning for Soil Spectroscopy Based on Convolutional Neural Networks and Its Application in Soil Clay Content Mapping Using Hyperspectral Imagery 55
4.1 Abstract 55
4.2 Introduction 56
4.3 Materials and Methods 59
4.3.1 Datasets 59
4.3.2 Methods 62
4.3.3 Assessment 67
4.4 Results and Discussion 67
4.4.1 Interpretation of mineral and organic soils from LUCAS dataset 67
4.4.2 1D-CNN and spectral index for LUCAS soil clay content estimation 69
4.4.3 Application of transfer learning for soil clay content mapping using the pre-trained 1D-CNN model 72
4.4.4 Comparison between spectral index and transfer learning 74
4.4.5 Large-scale soil spectral library for digital soil mapping at the local scale using hyperspectral imagery 75
4.5 Conclusions 75
5 A Case Study of Forced Invariance Approach for Soil Salinity Estimation in Vegetation-Covered Terrain Using Airborne Hyperspectral Imagery 77
5.1 Abstract 78
5.2 Introduction 78
5.3 Materials and Methods 81
5.3.1 Study area of Zhangye Oasis 81
5.3.2 Data description 82
5.3.3 Methods 83
5.3.3 Model performance assessment 85
5.4 Results and Discussion 86
5.4.1 The correlation between NDVI and soil salinity 86
5.4.2 Vegetation suppression performance using the Forced Invariance Approach 86
5.4.3 Estimation of soil properties using airborne hyperspectral data 88
5.5 Conclusions 90
6 Conclusions and Outlook 93
Bibliography 97
Acknowledgements 11