Stephanie Helmling

Dr. Stephanie Helmling

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 May 2024 in Microscopy and Microanalysis
Verified
Journal Article
Closed access
PDF file
LNLars Nieradzik
Lars Nieradzik
JSJördis Sieburg-Rockel
Jördis Sieburg-Rockel
SHStephanie Helmling
Stephanie Helmling
JKJanis Keuper
Janis Keuper
TWThomas Weibel
Thomas Weibel
HSHenrike Stephani
Henrike Stephani
We have developed a methodology for the systematic generation of a large image dataset of macerated wood references, which we used to generate image data for nine hardwood genera. This is the basis for a substantial approach to automate, for the first time, the identification of hardwood species in microscopic images of fibrous materials by deep learning. Our methodology includes a flexible pipeline for easy annotation of vessel elements. We compare the performance of different neural network architectures and hyperparameters. Our proposed method performs similarly well to human experts. In the future, this will improve controls on global wood fiber product flows to protect forests.

30 October 2024 in Forests
Verified
Journal Article
Open access
PDF file
LNLars Nieradzik
Lars Nieradzik
HSHenrike Stephani
Henrike Stephani
JSJördis Sieburg-Rockel
Jördis Sieburg-Rockel
SHStephanie Helmling
Stephanie Helmling
AOAndrea Olbrich
Andrea Olbrich
JKJanis Keuper
Janis Keuper
Wood species identification plays a crucial role in various industries, from ensuring the legality of timber products to advancing ecological conservation efforts. This paper introduces WoodYOLO, a novel object detection algorithm specifically designed for microscopic wood fiber analysis. Our approach adapts the YOLO architecture to address the challenges posed by large, high-resolution microscopy images and the need for high recall in localization of the cell type of interest (vessel elements). Our results show that WoodYOLO significantly outperforms state-of-the-art models, achieving performance gains of 12.9% and 6.5% in F2 score over YOLOv10 and YOLOv7, respectively. This improvement in automated wood cell type localization capabilities contributes to enhancing regulatory compliance, supporting sustainable forestry practices, and promoting biodiversity conservation efforts globally.

18 February 2024 in arXiv
Verified
Preprint
Open access
PDF file
LNLars Nieradzik
Lars Nieradzik
HSHenrike Stephani
Henrike Stephani
JSJördis Sieburg-Rockel
Jördis Sieburg-Rockel
SHStephanie Helmling
Stephanie Helmling
AOAndrea Olbrich
Andrea Olbrich
JKJanis Keuper
Janis Keuper
In this study, we explore the explainability of neural networks in agriculture and forestry, specifically in fertilizer treatment classification and wood identification. The opaque nature of these models, often considered 'black boxes', is addressed through an extensive evaluation of state-of-the-art Attribution Maps (AMs), also known as class activation maps (CAMs) or saliency maps. Our comprehensive qualitative and quantitative analysis of these AMs uncovers critical practical limitations. Findings reveal that AMs frequently fail to consistently highlight crucial features and often misalign with the features considered important by domain experts. These discrepancies raise substantial questions about the utility of AMs in understanding the decision-making process of neural networks. Our study provides critical insights into the trustworthiness and practicality of AMs within the agriculture and forestry sectors, thus facilitating a better understanding of neural networks in these application areas.

19 January 2026 in Holzforschung
Verified
Journal Article
Open access
PDF file
JSJördis Sieburg-Rockel
Jördis Sieburg-Rockel
SHStephanie Helmling
Stephanie Helmling
LNLars Nieradzik
Lars Nieradzik
SWStephanie Wrage
Stephanie Wrage
TWThomas Weibel
Thomas Weibel
AOAndrea Olbrich
Andrea Olbrich
The conversion of processes controlled by human expertise and know-how into automated operations is the goal of a wide range of modern research. This study reports on a blind test in which twelve unknown samples were analyzed by human experts and an AI system developed to check the genera of hardwoods used in paper production. Trained to detect hardwood cells in microscopic images of maceration slides, it assigns them to the nine most commonly used hardwood species. Softwoods were also added to the samples, to make the test as realistic as possible. Human experts achieved an accuracy of 0.96 for recognizing a genus contained in a sample. The two-stage machine recognition system achieved an accuracy of 0.79 at the defined threshold values of 0.7 for object recognition and 0.75 for genus probability. Human experts failed to recognize some genera contained in the samples, whereas the AI models did not miss any genus at these thresholds. A comparison of the results revealed the strengths and weaknesses of the independent methods. This study is an important step towards optimizing the automated image recognition system developed to support the implementation of the European Union Deforestation Regulation (EUDR) with regard to deforestation-free products/supply chains.

24 July 2023 in arXiv
Verified
Preprint
Open access
PDF file
LNLars Nieradzik
Lars Nieradzik
JSJördis Sieburg-Rockel
Jördis Sieburg-Rockel
SHStephanie Helmling
Stephanie Helmling
JKJanis Keuper
Janis Keuper
TWThomas Weibel
Thomas Weibel
HSHenrike Stephani
Henrike Stephani
We have developed a methodology for the systematic generation of a large image dataset of macerated wood references, which we used to generate image data for nine hardwood genera. This is the basis for a substantial approach to automate, for the first time, the identification of hardwood species in microscopic images of fibrous materials by deep learning. Our methodology includes a flexible pipeline for easy annotation of vessel elements. We compare the performance of different neural network architectures and hyperparameters. Our proposed method performs similarly well to human experts. In the future, this will improve controls on global wood fiber product flows to protect forests.

18 November 2024 in arXiv
Verified
Preprint
Open access
PDF file
LNLars Nieradzik
Lars Nieradzik
HSHenrike Stephani
Henrike Stephani
JSJördis Sieburg-Rockel
Jördis Sieburg-Rockel
SHStephanie Helmling
Stephanie Helmling
AOAndrea Olbrich
Andrea Olbrich
JKJanis Keuper
Janis Keuper
Wood species identification plays a crucial role in various industries, from ensuring the legality of timber products to advancing ecological conservation efforts. This paper introduces WoodYOLO, a novel object detection algorithm specifically designed for microscopic wood fiber analysis. Our approach adapts the YOLO architecture to address the challenges posed by large, high-resolution microscopy images and the need for high recall in localization of the cell type of interest (vessel elements). Our results show that WoodYOLO significantly outperforms state-of-the-art models, achieving performance gains of 12.9% and 6.5% in F2 score over YOLOv10 and YOLOv7, respectively. This improvement in automated wood cell type localization capabilities contributes to enhancing regulatory compliance, supporting sustainable forestry practices, and promoting biodiversity conservation efforts globally.