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arxiv: 1907.03278 · v1 · pith:2XDODGF7new · submitted 2019-07-07 · 📡 eess.SP · physics.geo-ph

Stacked autoencoders based machine learning for noise reduction and signal reconstruction in geophysical data

Pith reviewed 2026-05-25 01:28 UTC · model grok-4.3

classification 📡 eess.SP physics.geo-ph
keywords autoencodersdenoisinggeophysical datamachine learningsignal reconstructionnoise reductionstacked networks
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The pith

Stacked autoencoders reconstruct clean geophysical signals from noisy inputs by learning a lower-dimensional hidden representation.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper establishes that autoencoders can be trained to output the noise-free component of geophysical data even when the input contains noise. It introduces a stacked deep autoencoder trained in two stages: first initializing weights locally with single-hidden-layer autoencoders, then optimizing the full network. This is shown to work on a basic mathematical case and multiple geophysical examples, where the output data has substantially less noise than the input. A reader would care because geophysical measurements are routinely contaminated by noise that standard filters may not fully separate from the underlying signal.

Core claim

Autoencoders project input data nonlinearly onto a lower-dimensional hidden space in which important features are highlighted; even when the input is noisy, the network can be trained so that the reconstruction step recovers the clean signal component. The stacked variant uses local pretraining on basic single-hidden-layer autoencoders to set initial weights before full-network training, and this procedure reduces noise across all examined mathematical and geophysical cases.

What carries the argument

Stacked autoencoder with two-step training, in which single-hidden-layer autoencoders first learn local weights that initialize the deeper network before joint optimization of the full model.

If this is right

  • The same two-step stacked training produces usable denoised versions of both synthetic and field geophysical datasets.
  • Feature highlighting in the hidden space improves downstream interpretation of the reconstructed signals.
  • The method operates without an explicit parametric model of the noise distribution.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The approach may transfer to other measurement domains where signals share consistent low-dimensional structure across examples.
  • Performance could degrade if the training set lacks sufficient variety in signal patterns relative to the noise.
  • Extending the architecture depth or adding regularization terms might further separate signal from noise on larger datasets.

Load-bearing premise

The lower-dimensional representation learned from noisy data encodes the clean geophysical signal rather than a blend of signal and noise patterns.

What would settle it

Running the trained stacked autoencoder on held-out noisy geophysical traces yields outputs whose noise level is not lower than the input or whose signal features deviate from known clean reference traces.

Figures

Figures reproduced from arXiv: 1907.03278 by Debjani Bhowick, Deepak K. Gupta, Saumen Maiti, Uma Shankar.

Figure 1
Figure 1. Figure 1: Schematic structure of a traditional neural network. For [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Schematic diagram of a denoising autoencoder showing the encoder and decoder segments. [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Schematic diagram of a stacked denoising autoencoder showing the two steps involved in the [PITH_FULL_IMAGE:figures/full_fig_p005_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: (a) Relative noise reduction η for the 100 noisy test samples, (b) noise-free, noisy and autoen￾coder (AE) corrected data for sample index 20 and (c) for sample index 70. A denoising autoencoder comprising 2 hidden layers with 20 neurons in each is used. functions are used for projection from the input layer to hidden layer 1 and hidden layer 1 to hidden layer 2. For obtaining the output z, linear activati… view at source ↗
Figure 5
Figure 5. Figure 5: Schematic diagram of a buried vertical cylinder, also showing some of the parameters that [PITH_FULL_IMAGE:figures/full_fig_p008_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Noise-free, noisy and autoencoder (AE) corrected data for samples with index 27, 73 and 282. [PITH_FULL_IMAGE:figures/full_fig_p010_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: An example seismic section considered for generating the training and test samples for this [PITH_FULL_IMAGE:figures/full_fig_p011_7.png] view at source ↗
Figure 8
Figure 8. Figure 8: Schematic diagram demonstrating the extraction of small image slices from a test image of [PITH_FULL_IMAGE:figures/full_fig_p011_8.png] view at source ↗
Figure 9
Figure 9. Figure 9: Denoising of corrupted seismic data using a traditional deep autoencoder and a stacked deep [PITH_FULL_IMAGE:figures/full_fig_p012_9.png] view at source ↗
Figure 10
Figure 10. Figure 10: Schematic diagram of an m × n image slice provided as a training sample to the denoising autoencoder. Here, the superscripts 1, 2, 3, . . ., n denote the features used for training. For the well data denoising problem considered in this paper, the features are porosity, saturation, p-wave velocity and clay content. To denoise the i th data point in the well logs, the image slice includes information of m−… view at source ↗
Figure 11
Figure 11. Figure 11: Noisefree, noisy and autoencoder (AE) corrected [PITH_FULL_IMAGE:figures/full_fig_p016_11.png] view at source ↗
Figure 12
Figure 12. Figure 12: Noisefree, noisy and autoencoder (AE) corrected porosity values [PITH_FULL_IMAGE:figures/full_fig_p016_12.png] view at source ↗
Figure 13
Figure 13. Figure 13: Noisefree, noisy and autoencoder (AE) corrected [PITH_FULL_IMAGE:figures/full_fig_p016_13.png] view at source ↗
read the original abstract

Autoencoders are neural network formulations where the input and output of the network are identical and the goal is to identify the hidden representation in the provided datasets. Generally, autoencoders project the data nonlinearly onto a lower dimensional hidden space, where the important features get highlighted and interpretation of the data becomes easier. Recent studies have shown that even in the presence of noise in the input data, autoencoders can be trained to reconstruct the noisefree component of the data from the reduced-dimensional hidden space. In this paper, we explore the application of autoencoders within the scope of denoising geophysical datasets using a data-driven methodology. The autoencoder formulation is discussed, and a stacked variant of deep autoencoders is proposed. The proposed method involves locally training the weights first using basic autoencoders, each comprising a single hidden layer. Using these initialized weights as starting points in the optimization model, the full autoencoder network is then trained in the second step. The applicability of denoising autoencoders has been demonstrated on a basic mathematical example and several geophysical examples. For all the cases, autoencoders are found to significantly reduce the noise in the input data.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

3 major / 2 minor

Summary. The paper proposes a two-stage stacked autoencoder architecture (local pre-training of single-hidden-layer autoencoders followed by end-to-end fine-tuning) for denoising geophysical signals. It applies the method to a synthetic mathematical example and several geophysical datasets, asserting that the approach significantly reduces noise in the input data for all examined cases.

Significance. If the central claim were supported by objective metrics and independent validation, the work would offer a practical data-driven alternative for noise suppression in geophysical signal processing. The two-stage training is a standard initialization technique, but its utility here depends on demonstrating genuine signal recovery rather than generic compression.

major comments (3)
  1. [Abstract] Abstract: the assertion that autoencoders 'significantly reduce the noise' for all cases supplies no quantitative metrics (SNR improvement, MSE, or similar), error bars, or baseline comparisons, leaving the central empirical claim unsupported.
  2. [Geophysical examples] Geophysical examples section: without ground-truth clean signals, visual inspection cannot confirm that the hidden representation isolates the geophysical signal rather than performing dimensionality-reduction smoothing; any sufficiently compressive autoencoder could yield comparable visual results.
  3. [Method and results] Method and results: training and evaluation are performed on the identical noisy observations, so reported reconstruction quality is a fitted quantity whose value depends on architecture and optimization choices rather than an independent test of signal recovery.
minor comments (2)
  1. [Method] The description of the two-stage training procedure would benefit from an explicit diagram or pseudocode to clarify the local pre-training versus global fine-tuning steps.
  2. [Autoencoder formulation] Notation for encoder/decoder weights and hidden-layer dimensions is introduced without a consolidated table, making it harder to reproduce the exact architectures used.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for the constructive feedback on our manuscript. We address each major comment below, indicating where revisions will be incorporated to strengthen the presentation of our results.

read point-by-point responses
  1. Referee: [Abstract] Abstract: the assertion that autoencoders 'significantly reduce the noise' for all cases supplies no quantitative metrics (SNR improvement, MSE, or similar), error bars, or baseline comparisons, leaving the central empirical claim unsupported.

    Authors: The abstract condenses the visual evidence from the figures. We agree that quantitative support would improve clarity. In revision we will insert SNR and MSE values (with the synthetic mathematical example, where a clean reference is available) and will explicitly qualify the real-data cases as relying on visual assessment. revision: yes

  2. Referee: [Geophysical examples] Geophysical examples section: without ground-truth clean signals, visual inspection cannot confirm that the hidden representation isolates the geophysical signal rather than performing dimensionality-reduction smoothing; any sufficiently compressive autoencoder could yield comparable visual results.

    Authors: Ground-truth clean signals are unavailable for the field geophysical datasets, a common constraint in the domain. The two-stage training procedure is intended to encourage recovery of structured signal components rather than generic smoothing. We will add side-by-side comparisons against standard denoising baselines (e.g., wavelet thresholding) to provide additional evidence that the learned representation offers advantages beyond simple compression. revision: yes

  3. Referee: [Method and results] Method and results: training and evaluation are performed on the identical noisy observations, so reported reconstruction quality is a fitted quantity whose value depends on architecture and optimization choices rather than an independent test of signal recovery.

    Authors: Autoencoder denoising is unsupervised by design; the network is trained to reconstruct its noisy input through a bottleneck. For the synthetic example an independent clean reference exists and will be used for explicit error quantification. We will revise the text to state this distinction clearly and, where data volume permits, introduce a hold-out subset for the synthetic case to illustrate generalization. revision: partial

Circularity Check

0 steps flagged

No circularity; empirical demonstration on provided examples is self-contained

full rationale

The paper describes a data-driven application of stacked autoencoders trained end-to-end on the input geophysical datasets themselves to produce reconstructions. No first-principles derivation, uniqueness theorem, or parameter-free prediction is claimed that reduces by construction to the training inputs. Results are presented as empirical demonstrations on a mathematical example and geophysical cases, which constitutes standard supervised evaluation rather than a circular reduction. No self-citations or ansatzes are invoked as load-bearing steps in the provided text.

Axiom & Free-Parameter Ledger

2 free parameters · 1 axioms · 0 invented entities

The method rests on standard neural-network assumptions plus hyperparameters chosen during training. No new physical entities are postulated.

free parameters (2)
  • network depth and hidden-layer widths
    Chosen to match data dimensionality and to allow a bottleneck representation.
  • learning rate, batch size, and number of epochs
    Tuned so that the optimization converges on the given datasets.
axioms (1)
  • domain assumption A neural network with a bottleneck layer can separate repeatable signal structure from uncorrelated noise when trained on many examples.
    Invoked when the authors state that the autoencoder reconstructs the noisefree component.

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Reference graph

Works this paper leans on

66 extracted references · 52 canonical work pages · 2 internal anchors

  1. [1]

    URL https://www.tensorflow.org/, software available from tensorflow.org

    Abadi M, Agarwal A, Barham P, Brevdo E, Chen Z, Citro C, Corrado GS, Davis A, Dean J, Devin M, Ghemawat S, Goodfellow I, Harp A, Irving G, Isard M, Jia Y, Jozefowicz R, Kaiser L, Kudlur M, Levenberg J, Man´ e D, Monga R, Moore S, Murray D, Olah C, Schuster M, Shlens J, Steiner B, Sutskever I, Talwar K, Tucker P, Vanhoucke V, Vasudevan V, Vi´ egas F, Vinya...

  2. [2]

    Geophysics 68:1202–1210

    Abdelrehman EM, El-Araby TM, Hassaneen AG, Hafez MA (2003) New methods for shape and depth determinations from SP data. Geophysics 68:1202–1210

  3. [3]

    Cogni- tive Sci 9:147–169

    Ackley DH, Hinton GE, Sejnowski TJ (1985) A learning algorithm for boltzmann machines. Cogni- tive Sci 9:147–169

  4. [4]

    Neural Networks 2:53–58

    Baldi P, Hornik K (1989) Neural networks and principal component analysis: Learning from exam- ples without local minima. Neural Networks 2:53–58

  5. [5]

    J Manage Inform Syst 10:11–32

    Bansal A, Kauffman RJ, Weitz RR (1993) Comparing the modeling performance of regression and neural networks as data quality varies: a business value approach. J Manage Inform Syst 10:11–32

  6. [6]

    Comput Math Appl 64:3580–3593 18

    Beenamol M, Prabavathy S, Mohanalin J (2012) Wavelet based seismic signal de-noising using shannon and tsallis entropy. Comput Math Appl 64:3580–3593 18

  7. [7]

    Foundations and Trends in Machine Learning 2(1):1–127

    Bengio Y (2009) Learning deep architectures for AI. Foundations and Trends in Machine Learning 2(1):1–127

  8. [8]

    In: 78th EAGE Conf

    Bhowmick D, Shankar U, Maiti S (2016) Revisiting supervised learning in the context of predicting gas hydrate saturation. In: 78th EAGE Conf. Exhib., pp 1–4

  9. [9]

    Deep Autoassociative Neural Networks for Noise Reduction in Seismic data

    Bhowmick D, Gupta DK, Maiti S, Shankar U (2018) Deep autoassociative neural networks for noise reduction in seismic data. CoRR abs/1805.00291

  10. [10]

    Image denoising with multi-layer perceptrons, part 1: comparison with existing algorithms and with bounds

    Burger CH, Schuler CJ, Harmeling S (2012) Image denoising with multi-layer perceptrons, part 1: comparison with existing algorithms and with bounds. CoRR 1211.1544

  11. [11]

    MIT Press, Cambridge, MA

    Chapelle O, Scholkopf B, Zien A (2006) Semi-supervised learning. MIT Press, Cambridge, MA

  12. [12]

    In: Proc

    Chauvin Y (1989) Towards a connectionist model of symbolic emergence. In: Proc. 11th Ann. Conf. of the Cognitive Science Soc., pp 580–1587

  13. [13]

    Pers Psychol 46(3):503–522

    Collins JM, Clark MR (1993) An application of the theory of neural computation to the prediction of workplace behavior: an illustration and assessment of network analysis. Pers Psychol 46(3):503–522

  14. [14]

    In: Proc

    Cottrell GW, Munro P, Zipser D (1987) Learning internal representations from gray-scale images: an example of extensional programming. In: Proc. 9th Ann. Conf. of the Cognitive Science Soc., pp 461–473

  15. [15]

    Ecol Model 240:113–122

    Crisci C, Ghattas B, Perera G (2012) A review of supervised machine learning algorithms and their applications to ecological data. Ecol Model 240:113–122

  16. [16]

    Comput Sec 14(5):435–448

    Doumas A, Mavroudakis K, Gritzalis D, Katsikas S (1995) Design of a neural network for recognition and classification of computer viruses. Comput Sec 14(5):435–448

  17. [17]

    J Med Syst 36:2973–2980

    Feng F, Wu Y, Nie G, Ni R (2012) The effect of artificial neural network model combined with six tumor markers in auxillary diagnosis of lung cancer. J Med Syst 36:2973–2980

  18. [18]

    In: Proc

    Gupta DK, Arora Y, Singh UK, Gupta JP (2012) Recursive ant colony optimization for estimation of parameters of a function. In: Proc. RAIT-2012, IEEE, pp 1–7

  19. [19]

    Near Surf Geophys 11:325–339

    Gupta DK, Gupta JP, Arora Y, Shankar U (2013) Recursive ant colony optimization: a new tech- nique for the estimation of function parameters from geophysical field data. Near Surf Geophys 11:325–339

  20. [20]

    J Finance 11:325–339

    Hutchinson J, Lo AW, Poggio T (1994) A non-parametric approach to pricing and hedging derivative securities via learning networks. J Finance 11:325–339

  21. [21]

    In: Koller D, Schuurmans D, Bengio Y, Bottou L (eds) Advances in Neural Information Processing Systems 21, Curran Associates, Inc., pp 769–776

    Jain V, Sebastian S (2009) Natural image denoising with convolutional networks. In: Koller D, Schuurmans D, Bengio Y, Bottou L (eds) Advances in Neural Information Processing Systems 21, Curran Associates, Inc., pp 769–776

  22. [22]

    Geophy Prospec 55(5):749–760

    Jardani A, Revil A, Santos FAM, Fauchard C, Dupont JP (2007) Detection of preferential infiltration pathways in sinkholes using joint inversion of self-potential and EM-34 conductivity data. Geophy Prospec 55(5):749–760

  23. [23]

    Manag Finance 18(6):15–26

    Jenson HL (1992) Using neural networks for credit scoring. Manag Finance 18(6):15–26

  24. [24]

    Comput Meth Prog Bio 132:93– 103

    Jones DE, Ghandehari H, Facelli JC (2016) A review of the applications of data mining and machine learning for the prediction of biomedical properties of nanoparticles. Comput Meth Prog Bio 132:93– 103

  25. [25]

    Mech Syst Signal Pr 107:241–265

    Khan S, Yairi T (2018) A review on the application of deep learning in system health management. Mech Syst Signal Pr 107:241–265

  26. [26]

    Comput Struct Biotechnol J 13:8–17

    Kourou K, Exarchos TP, Exarchos KP, Karamouzis MV, Fotiadis DI (2015) Machine learning ap- plications in cancer prognosis and prediction. Comput Struct Biotechnol J 13:8–17

  27. [27]

    Computers Chem Engng 16(4):313–328 19

    Kramer MA (1992) Autoassociative neural networks. Computers Chem Engng 16(4):313–328 19

  28. [28]

    In: Proc

    Larochelle H, Erhan D, Courville A, Bergstra J, Bengio Y (2007) An empirical evaluation of deep ar- chitectures on problems with many factors of variation. In: Proc. 24th Int. Conf. Machine Learning, ICML, pp 536–543

  29. [29]

    IEEE J Sel Top Appl

    Li J, Zhang Y, Qi R, Liu QH (2017) Wavelet-based higher order correlative stacking for seismic data denoising in the curvelet domain. IEEE J Sel Top Appl

  30. [30]

    Geophy J Int 169(2):733–746

    Maiti S, Tiwari RK, K¨ umpel HJ (2007) Neural network modelling and classification of lithofacies using well log data: A case study from ktb borehole site. Geophy J Int 169(2):733–746

  31. [31]

    Cambridge University Press, Cambridge

    Mavko G, Mukerji T, Dvorkin J (2009) The Rock Physics Handbook: Tools for Seismic Analysis of Porous Media. Cambridge University Press, Cambridge

  32. [32]

    Geophysics 58:67–78

    McCormack MD, Zaucha DE, Dushek DW (1993) First-break refraction event picking and seismic data trace editing using neural networks. Geophysics 58:67–78

  33. [33]

    Geophys Prosp 10:203–218

    Meiser P (1962) A method of quantitative interpretation of self-potential measurements. Geophys Prosp 10:203–218

  34. [34]

    Geo- phys Prosp 40:587–604

    Murat ME, Rudman AJ (1992) Automated first arrival picking: A neural network approach. Geo- phys Prosp 40:587–604

  35. [35]

    Expert Syst 11(4):245–250

    Nikolopoulos C, Fellrath P (1994) A hybrid expert system for investment advising. Expert Syst 11(4):245–250

  36. [36]

    In: 15th Int

    Ojha U, Garg A (2016) Denoising high resolution multispectral images using deep learning approach. In: 15th Int. Conf. Machine Learning and Appl., IEEE, pp 1–5

  37. [37]

    IEEE T Image Process 11(5):545–557

    Pizurica A, Philips W, Lemahieu I, Acheroy M (2002) A joint inter- and intrascale statistical model for bayesian wavelet based image denoising. IEEE T Image Process 11(5):545–557

  38. [38]

    IEEE T Image Process 12(11):1338–1351

    Portilla J, Strela V, Wainright MJ, Simoncelli EP (2003) Image denoising using scale mixtures of gaussians in the wavelet domain. IEEE T Image Process 12(11):1338–1351

  39. [39]

    Geophysics 57:1534–1544

    Poulton MM, Sternberg BK, Glass CE (1992) Location of subsurface targets in geophysical data using neural networks. Geophysics 57:1534–1544

  40. [40]

    Int J Manpower 12(8):18–21

    Proctor RA (1991) An expert system to aid in staff selection: a neural network approach. Int J Manpower 12(8):18–21

  41. [41]

    In: Proc

    Raymer LL, Hunt ER, Gardner JS (1980) An improved sonic transit time-to-porosity transform. In: Proc. SPWLA 21st Annual Logging Symposium, pp 1–13

  42. [42]

    In: Proc

    Reading AM, Cracknell MJ, Bombardieri DJ, Chalke T (2015) Combining machine learning and geophysical inversion for applied geophysics. In: Proc. ASEG-PESA 2015 Conf., pp 1–4

  43. [43]

    AI Expert 10:29–33

    Rogers J (1995) Neural network user authentication. AI Expert 10:29–33

  44. [44]

    In: Platt JC, Koller D, Singer Y, Roweis S (eds) Advances in Neural Information Processing Systems 19 (NIPS06), MIT Press, pp 1137–1144

    Ronzato M, Poultney CS, Chopra S, LeCun Y (2007) Efficient learning of sparse representations with an energy-based model. In: Platt JC, Koller D, Singer Y, Roweis S (eds) Advances in Neural Information Processing Systems 19 (NIPS06), MIT Press, pp 1137–1144

  45. [45]

    Mar Pet Geo 28(2):311 – 331

    Rose K, Boswell R, Collett T (2011) Mount elbert gas hydrate stratigraphic test well, alaska north slope: Coring operations, core sedimentology, and lithostratigraphy. Mar Pet Geo 28(2):311 – 331

  46. [46]

    J Geophys R 99:6753– 6768

    R¨ oth G, Tarantola A (1994) Neural networks and inversion of seismic data. J Geophys R 99:6753– 6768

  47. [47]

    Int J Comput Vision 82(2):205–229

    Roth S, Black MJ (2009) Fields of experts. Int J Comput Vision 82(2):205–229

  48. [48]

    Physica D 60:259–268

    Rudin LI, Osher S, Fatemi E (1992) Nonlinear total variation based noise removal algorithms. Physica D 60:259–268

  49. [49]

    Futures 23(9):42–44 20

    Ruggiero Jr MA (1994) Training neural networks for intermarket analysis. Futures 23(9):42–44 20

  50. [50]

    Decis Sci 23:899–196

    Salchenberger LM, Cinar EM, Lash NA (1992) Neural networks: a new tool for predicting thrift failures. Decis Sci 23:899–196

  51. [51]

    Comput Geosci 36:1185–1190

    Santos FAM (2010) Inversion of self-potential of idealized bodies’ anomalies using particle swarm optimization. Comput Geosci 36:1185–1190

  52. [52]

    Earth Planets Space 54:655–662

    Santos FAM, Almeida EP, Castro R, Nolasco M, Mendes-Victor L (2002) A hydrogeological inves- tigation using em34 and sp surveys. Earth Planets Space 54:655–662

  53. [53]

    In: Proc

    Schuler CJ, Burger HC, Harmeling S, Scholkopf B (2013) A machine learning approach for non-blind image deconvolution. In: Proc. IEEE Conf. Comp. Vision Patt. Recog. (CVPR), pp 1067–1074

  54. [54]

    J Petrol Sci Eng 106:62–70

    Shankar U, Gupta DK, Bhowmick D, Sain K (2013) Gas hydrate and free gas saturations using rock physics modelling at site nghp-01-05 and 07 in the krishnagodavari basin, eastern indian margin. J Petrol Sci Eng 106:62–70

  55. [55]

    IEEE Trans Softw Eng 18(7):590–600

    Stafylopatis A, Likas A (1992) Pictorial information retrieval using the random neural network. IEEE Trans Softw Eng 18(7):590–600

  56. [56]

    Geophysics 63:1551–1555

    Sundararajan N, Rao PS, Sunitha V (1998) An analytical method to interpret self-potential anoma- lies caused by 2d inclined sheets. Geophysics 63:1551–1555

  57. [57]

    In: Proc

    Tomasi C, Manduchi R (1998) Bilateral filtering for gray and color images. In: Proc. 6th Int. Conf. Comp. Vision (ICCV), pp 839–846

  58. [58]

    Expert Syst Appl 36(10):11994–12000

    Tsai C, Hsu Y, Lin C, Lin W (2009) Intrusion detection by machine learning: A review. Expert Syst Appl 36(10):11994–12000

  59. [59]

    Geophys J Int 189(3):1183–1202

    Valentine AP, Trampert J (2012) Data space reduction, quality assessment and searching of seismo- grams: autoencoder networks for waveformdata. Geophys J Int 189(3):1183–1202

  60. [60]

    Geophys Res Lett 40(12):3048–3054

    Valentine AP, Kalnins LM, Trampert J (2013) Discovery and analysis of topographic features using learning algorithms: A seamount case study. Geophys Res Lett 40(12):3048–3054

  61. [61]

    J Mach Learn Res 11:3371–3408

    Vincent P, Larochelle H, Lajoie I, Bengio Y, Manzagol PA (2010) Stacked denoising autoencoders: Learning useful representations in a deep network with a local denoising criterion. J Mach Learn Res 11:3371–3408

  62. [62]

    ECMI Series, Teubner-Verlag, Stuttgart, Germany

    Weickert J (1998) Anisotropic diffusion in image processing. ECMI Series, Teubner-Verlag, Stuttgart, Germany

  63. [63]

    IEEE Int

    Weiss Y, Freeman WT (2007) What makes a good model of natural images? In: Proc. IEEE Int. Conf. Comp. Vis. Patt. Recog. (CVPR), pp 1–8

  64. [64]

    Comput Geosci 86:75–82

    Xiong Y, Zuo R (2016) Recognition of geochemical anomalies using a deep autoencoder network. Comput Geosci 86:75–82

  65. [65]

    Geophys Prosp 45:725–743

    Zhang Y, Paulson KV (1997) Magnetotelluric inversion using regularized hopfield neural networks. Geophys Prosp 45:725–743

  66. [66]

    Surveys Geophy 24:291–338 21

    Zlotnini J, Nishida Y (2003) Review on morphological insights of self-potential anomalies on volca- noes. Surveys Geophy 24:291–338 21