About
I'm a Senior Machine Learning Engineer at Pento and a PhD in Computer Vision with over 5 years of experience developing deep learning solutions for image segmentation and analysis.
I completed my PhD thesis on automatic tree-ring detection and analysis, developing novel deep learning architectures and open-source tools now used by the dendrochronology research community worldwide. This work was recognized with First Prize in the Electrical Engineering category by the National Academy of Engineering of Uruguay (ANIU).
News
- May 2026 TRAS accepted — Forestry, An International Journal of Forest Research
- Dec 2025 First Prize — Doctoral Thesis in Electrical Engineering (ANIU)
- Dec 2025 UruDendro4 presented at ICPRS-25, Viña del Mar, Chile
- Sep 2025 Joined Pento as Senior ML Engineer
- Sep 2025 DeepCS-TRD presented at ICIAP, Rome, Italy
- Aug 2025 PhD completed — Universidad de la República
- 2025 UruDendro dataset family (UruDendro – UruDendro4) published on Zenodo
Awards & Recognition
First Prize — Doctoral Thesis in Electrical Engineering 2025
National Academy of Engineering of Uruguay (ANIU), awarded for the doctoral thesis
Application of Image Processing and Artificial Intelligence Techniques for the
Automatic Dendrometry of Native and Commercial Wood Species.
Research
My research focuses on creating efficient, explainable, and impactful AI systems for challenging domains including dendrochronology, medical imaging, and scientific image analysis. I specialize in deep learning architectures for image segmentation, boundary detection, and real-world image analysis workflows.
All projects fall within the same research line: automatic tree ring detection in wood cross-section images, covering three sub-lines — graphical user interface, computer vision algorithms, and dataset generation.
Graphical User Interface
TRAS – Tree Ring Analyzer Suite
Professional dendrochronology software with state-of-the-art CV & DL methods. A complete GUI application built with PyQt5 for automatic tree-ring detection and measurement. It integrates multiple detection methods (APD, CS-TRD, DeepCS-TRD), preprocessing tools, scale calibration, and professional data export capabilities.
Python PyQt5 PyTorch OpenCV
Computer Vision Algorithms
Automatic Tree Ring Detection
Research on automatic tree ring detection in macro images. Developed DeepCS-TRD (deep learning, U-Net-based) and CS-TRD (classical computer vision approach) for tree ring detection, and broadly tested the INBD method for tree ring segmentation. Work includes annotated datasets, benchmarking scripts, and pre-trained models.
PyTorch U-Net Computer Vision
Dataset Generation
Annotated datasets are mandatory for building tree-ring detection algorithms, are crucial for training and evaluating their performance, and are essential for obtaining accurate results. The datasets are specific for each species under consideration. These datasets were produced in collaboration with multidisciplinary teams, where I contributed as an image processing expert and software developer, working alongside domain specialists with the actual dendrochronological knowledge.
- UruDendro — 64 cross-section images of Pinus taeda L. with annotated annual rings
- UruDendro2 — 53 cross-section images of Pinus taeda L. with earlywood–latewood annotations
- UruDendro3a — 9 cross-section images of Gleditsia triacanthos L.
- UruDendro4 — 102 benchmark images of Pinus taeda L. for ML model development
- Salix glauca — 50 cross-section images from Arctic shrub samples (Greenland)
Experience
Senior ML Engineer
Pento — Hybrid
Sep 2025 – Present
ML Engineer (Freelance)
MISMO — San Francisco, USA
Mar 2025 – Apr 2025
Designed and implemented a containerized system that automatically detects and crops the primary speaker in long-format videos for social media (9:16 vertical output). Integrated MediaPipe BlazePose with scene-change detection and linear interpolation for smooth virtual camera movement. Processed 2-hour videos in under 45 minutes.
Python MediaPipe OpenCV Docker
ML Engineer (Freelance)
IATech-Conaprole — Montevideo, Uruguay
Jul 2024 – Aug 2024
Developed an image analysis tool to estimate shelf space occupied by specific products in grocery store images, framed as a dense object detection task.
YOLOv5 GCP OpenCV Python
ML Engineer
Digital Sense — Montevideo, Uruguay
Nov 2021 – Jun 2024
Worked across multiple computer vision projects: pose-based workout feedback using landmark rules; multiband satellite image registration with deep feature extraction and robust match filtering; and object detection on edge devices (Android GPU, YOLOv5) and surveillance cameras (speed analysis with Kalman filtering).
PyTorch TensorFlow MediaPipe Snowflake Docker C++
Service Engineer / Junior Developer
Isbel S.A. — Montevideo, Uruguay
Feb 2018 – Oct 2021
Supported AMI telemeasurement platforms and live/VOD video streaming systems (H.264, HEVC, HLS/DASH). Built a Grafana + Prometheus monitoring dashboard for video processing clusters.
Docker Grafana Linux Python C++
Selected Publications
For a complete list, visit my Google Scholar profile
Recent Journal & Conference Papers
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Marichal, H., Passarella, D., Randall, G. (2026). TRAS: An Interactive Software for Tracing Tree Ring Cross Sections. Forestry, An International Journal of Forest Research. Accepted.
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Marichal, H., Blanco, J., Passarella, D., Randall, G. (2025). UruDendro4: A Benchmark Dataset for Automatic Tree-Ring Detection in Cross-Section Images of Pinus taeda L. IEEE 15th International Conference on Pattern Recognition Systems (ICPRS-25).
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Marichal, H., Casaravilla, V., Power, C., Mello, K., Profumo, L., Mazarino, J., Lucas, C., Passarella, D., Randall, G. (2025). DeepCS-TRD, a Deep Learning-based Cross-Section Tree Ring Detector. International Conference on Image Analysis and Processing (ICIAP).
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Marichal, H., Passarella, D., Lucas, C., Profumo, L., Casaravilla, V., Rocha Galli, M. N., Ambite, S., Randall, G. (2025). UruDendro, a public dataset of 64 cross-section images and manual annual ring delineations of Pinus taeda L. Annals of Forest Science.
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Marichal, H., Passarella, D., Randall, G. (2025). CS-TRD: a Cross-Section Tree Ring Detection Method. Image Processing On Line (IPOL).
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Marichal, H., Passarella, D., Randall, G. (2024). Automatic Wood Pith Detector: Local Orientation Estimation and Robust Accumulation. International Conference on Pattern Recognition (ICPR).
Under Review & Submitted
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Marichal, H., Power, C., Treier, U. A., Resente, G., Normand, S., Randall, G. (2024). Assessing automatic ring detection on microscopy images of Salix glauca. Under Review.
Thesis
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Marichal, H. (2025). Application of Image Processing and Artificial Intelligence Techniques for the Automatic Dendrometry of Native and Commercial Wood Species. Doctoral Thesis in Electrical Engineering, Universidad de la República. (Advisors: Gregory Randall and Diego Passarella).