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This repository aims to adaptive design the coded apertures from compressive spectral images acquired with a multisensor camera. The classification is performed using the captured compressive projections. 
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This repository contains tools to simulate the ground filtering process of a registered point cloud. The repository contain two filtering methods. The first method uses normal-vector, and fit to plane. The second method utilizes voxel adjacency, and fit to plane. This repository contains the code to reproduce the results presented in the paper following paper:
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Coloquio Department of Informatics Universidad Técnica Federico Santa MAría, in this coloquio section four applications of computational photography are presented: Multispectral demosaicking, ultrafast video, phase retrieval, and Multispectral extended depth-of-field:
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Research Thrusts
Published in Ingeniería e Investigación, 2015
Recommended citation: N. Diaz, H. Rueda, and H. Arguello. “High-dynamic range compressive spectral imaging by grayscale coded aperture adaptive filtering” Ingeniería e Investigación. vol. 35, pp. 53-60. 2015. [Paper], [DOI],[Open access].
Published in I+D revista de investigaciones, 2018
Recommended citation: E. Florez, N. Diaz, W. Goméz, L. Bautista and D. Delgado. “Evaluación de algoritmos bioinspirados para el problema de planificación de trabajos” I+D revista de investigaciones. vol. 1, pp. 133-143. 2018. [Paper], [DOI],[Open access].
Published in Applied Optics, 2018
Recommended citation: N. Diaz, H. Rueda, and H. Arguello. “Adaptive filter design via a gradient thresholding algorithm for compressive spectral imaging,” Applied Optics, vol. 57, pp. 4890-4900. 2018. [Paper], [DOI].
Published in Optics & Laser Technology, 2019
Recommended citation: N. Diaz, C. Hinojosa, and H. Arguello. “Adaptive grayscale compressive spectral imaging using optimal blue noise coding patterns,” Optics & Laser Technology, vol. 117, pp. 147-157. 2019. [Paper], [DOI], [Code].
Published in IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2021
Recommended citation: N. Diaz, J. Ramirez, E. Vera and H. Arguello, “Adaptive Multisensor Acquisition via Spatial Contextual Information for Compressive Spectral Image Classification” IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, vol. 14, pp. 9254-9266. 2021. [TechRxiv], [DOI], [Code].
Published in International Journal of Applied Earth Observation and Geoinformation, 2021
Recommended citation: N. Diaz, O. Gallo, J. Caceres, H. Porras. “Real-time ground filtering algorithm of cloud points acquired using Terrestrial Laser Scanner (TLS)” International Journal of Applied Earth Observation and Geoinformation,vol. 105, pp. 102629, 2021. [arXiv], [DOI], [Code].
Published in Optics Express, 2022
Recommended citation: E. Vera, F. Guzmán, and N. Diaz, “Shuffled rolling shutter for snapshot temporal imaging,” Opt. Express, vol. 30, pp. 887-901, 2022. [Paper], [DOI], [Code].
Published in IEEE Transactions on Image Processing, 2023
Recommended citation: N. Diaz, A. Alvarado, P. Meza, F. Guzmán and E. Vera, “Multispectral Filter Array Design by Optimal Sphere Packing,” IEEE Transactions on Image Processing, vol. 32, pp. 3634-3649, 2023. [DOI],[Paper], [TechRxiv], [Code], [ICASSP_2024_poster].
Published in Springer International Publishing, 2023
Recommended citation: E. Vera, F. Guzmán and N. Diaz, “Shuffled Rolling Shutter Camera,” Springer International Publishing, pp. 499-513, 2023. [DOI].
Published in Optics Express, 2025
Recommended citation: N. Diaz, M. Beniwal, M. Marquez, F. Guzmán, C. Jiang, J. Liang, and E. Vera, “Single-mask sphere-packing with implicit neural representation reconstruction for ultrahigh-speed imaging,” Optics Express 33, pp. 24027–24038, 2025. [DOI],[Paper].
Published in Optics & Laser Technology, 2025
Recommended citation: B. Romero, P. Scherz, N. Diaz, J. Tapia, A. Cofré, E. Peters, D Perez and E. Vera, “Phase Retrieval by Designed Hadamard Complementary Coded Apertures,” Optics & Laser Technology,, vol. 191, pp. 113311, 2025. [Optica open], [DOI], [Paper].
Published in IEEE Transactions on Image Processing, 2025
Recommended citation: F. Guzmán, N. Diaz, B. Romero, and E. Vera, “Scalable Coding for High-Resolution, High-Compression Ratio Snapshot Compressive Video,” IEEE Transactions on Image Processing, vol. 34, pp. 3960-3970, 2025. [DOI],[Paper], [Opticaopen], [Code].
Published in IEEE Open Journal on Signal Processing, 2025
Recommended citation: E. Oliva, N. Diaz, S. Pinilla, and E. Vera, “Multispectral Extended Depth-of-Field Imaging via Stochastic Wavefront Optimization,” IEEE Open Journal on Signal Processing, vol. 6, pp. 965 - 974, 2025. [DOI], [Code], [COSI_2025_poster].
Published in Elsevier, 2026
Recommended citation: James Skowronek, Felipe Guzmán, Nelson Díaz, Esteban Vera and David Brady, “Space-time imaging,” Elsevier, Vol. 54, pp. 119-145, 2026. [DOI].
Published in Scientific Reports, 2026
Recommended citation: Scherz, Pablo and Peters, Eduardo and Nelson Díaz and Tapia, Jorge and Romero, Bastián and Vera, Esteban and Pérez, Darío G, “High-resolution spatiotemporal reconstruction of complex optical fields enables direct testing of turbulence statistics,” Scientific Reports, 2026. [DOI].
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Recommended citation: N. Diaz, J. Luna, W. Gomez, and L. Bautista. “Algoritmo Inmune de Selección Clonal para el problema de Job Shop Scheduling,” Infornor Chile 2013 IV Congreso Internacional de Computación e Informática del Norte de Chile, Coquimbo. 2013. [Paper].
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Recommended citation: N. Diaz, H. Rueda, and H. Arguello. “High-dynamic range compressive spectral imaging by adaptive filtering,” 2015 3rd International Workshop on Compressed Sensing Theory and its Applications to Radar, Sonar and Remote Sensing (CoSeRa). 2015. [Paper], [Link], [Slides].
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Recommended citation: N. Diaz, H. Rueda, and H. Arguello. “Adaptive uniform grayscale coded aperture design for high dynamic range compressive spectral imaging,” Hyperspectral Imaging Sensors: Innovative Applications and Sensor Standards 2016. 2016. [Paper], [Link], [Slides].
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Recommended citation: N. Diaz, J. Bacca, and H. Arguello. “Gradient thresholding algorithm for adaptive colored coded aperture design in compressive spectral imaging,” in Imaging and Applied Optics 2017 (3D, AIO, COSI, IS, MATH, pcAOP), OSA Technical Digest (online) (Optica Publishing Group, 2017), paper JTu5A.4. [Paper], [Link], [Poster].
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Recommended citation: M. Marquez, N. Diaz, J. Bacca, S. Pertuz, and H. Arguello. “Compressive light field spectral imaging in a single-sensor device by using coded apertures,” in Imaging and Applied Optics 2017 (3D, AIO, COSI, IS, MATH, pcAOP), OSA Technical Digest (online) (Optica Publishing Group, 2017), paper CTh1B.5. [Paper], [Link], [Slides].
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Recommended citation: N. Diaz, A. Basarab, J. -Y. Tourneret and H. A. Fuentes. “Cardiac Motion Estimation Using Convolutional Sparse Coding,” 2019 27th European Signal Processing Conference (EUSIPCO), 2019, pp. 1-5, doi: 10.23919/EUSIPCO.2019.8903163. [Paper], [Link], [Slides].
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Recommended citation: N. Diaz, C. Noriega-Wandurraga, A. Basarab, J. -. Tourneret and H. Arguello. “Adaptive Coded Aperture Design by Motion Estimation using Convolutional Sparse Coding in Compressive Spectral Video Sensing” 2019 IEEE 8th International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP), 2019 pp. 445-449. [Paper], [Link], [Slides].
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Recommended citation: J. Bacca, N. Diaz and H. Arguello, “Compressive Classification via Deep Learning using Single-Pixel Measurements,” 2020 Data Compression Conference (DCC), 2020, pp. 359-359, doi: 10.1109/DCC47342.2020.00084. [Paper], [Link].
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Recommended citation: F. Guzmán, N. Díaz, and E. Vera. “Improved Compressive Temporal Imaging using a Shuffled Rolling Shutter,” in OSA Optical Sensors and Sensing Congress 2021 (AIS, FTS, HISE, SENSORS, ES), paper JTh6A.9. [Paper], [Link], [Poster].
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Recommended citation: A. Alvarado, N. Díaz, P. Meza, F. Guzmán, , and E. Vera. “Multispectral mosaic design using a sphere packing filter array,” in Imaging and Applied Optics Congress 2022 (3D, AOA, COSI, ISA, pcAOP), paper CTh4C.1. [Paper], [Link], [Presentation].
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Recommended citation: N. Díaz, A. Alvarado, P. Meza, and E. Vera. “Compressive spectral video by optimal 4D-sphere packing,” in Optica Imaging Congress (3D, COSI, DH, FLatOptics, IS, pcAOP), paper CM1E.4. [Paper], [Link], [Presentation].
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Recommended citation: A. Alvarado, N. Díaz, P. Meza, and E. Vera. “A sphere packing approach to design multiplexed multispectral filter arrays,” in Optica Imaging Congress (3D, COSI, DH, FLatOptics, IS, pcAOP), paper CTh2A.6. [Paper], [Link], [Presentation]
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Recommended citation: N. Díaz, and E. Vera. “Compressive Spectral-Video by Optimal 3D-Sphere Packing,” in 2023 IEEE Research and Applications of Photonics in Defense Conference (RAPID), TuE2: Spectral, Polarimetric, and Multimodal Imaging. [Paper], [Link], [Presentation].
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Recommended citation: B. Romero, N. Diaz, J. Tapia, and E. Vera. “Phase retrieval of elongated laser guide star by sphere packing coded apertures,” in Proc. SPIE 13097, Adaptive Optics Systems IX, 130973L, 22 June 2024. [Paper], [Link], [Poster]
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Recommended citation: N. Diaz, M. Beniwal, F. Guzmán, M. Marquez, J. Liang, and E. Vera. “Binary Coded Aperture Design by Sphere Packing in Compressive Ultrafast Photography,” in Optica Sensing Congress 2024 (AIS, LACSEA, Sensors, QSM), paper JF3A.4. [Paper], [Link], [Presentation]
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Recommended citation: A. Alvarado, N. Diaz, P. Meza, and E. Vera. “Multiplexed Multispectral Filter Array by 3D Sphere Packing Design,” in Optica Sensing Congress 2024 (AIS, LACSEA, Sensors, QSM), paper JF2A.8. [Paper], [Link], [Poster]
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Recommended citation: E. Oliva, N. Diaz, S. Pinilla, and E. Vera. “Data-driven Stochastic Wavefront Optimization for Multispectral Extended Depth-of-Field Imaging,” in Optica Imaging Congress 2025 (3D, DH, COSI, IS, pcAOP,RadIT), paper JW2A.7. [Paper], [Link], [Poster]
Undergraduate course, Universidad Industrial de Santander, Department of Computer Science Engineering, 2015
Undergraduate course, Universidad Industrial de Santander, Department of Electrical Engineering, 2016
Undergraduate course, Universidad de Investigación Y Desarrollo, Department of System Engineering, 2020
Undergraduate course, Universidad de Investigación Y Desarrollo, Department of System Engineering, 2020
Undergraduate course, Universidad de Investigación Y Desarrollo, Department of System Engineering, 2020
Undergraduate and graduate, courses in electrical engineering and computer science, 2025
Teaching Philosophy and Experience
Posgraduate course, Universidad Técnica Federico Santamaría, Campus Valparaíso, Department of Informatics, 2026
Summary