Johannes Brünger

Mr. Johannes Brünger

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

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

Representative Publications

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2 July 2020 in Sensors
Verified
Journal Article
Open access
PDF file
JBJohannes Brünger
Johannes Brünger
MGMaria Gentz
Maria Gentz
ITImke Traulsen
Imke Traulsen
RKReinhard Koch
Reinhard Koch
Behavioural research of pigs can be greatly simplified if automatic recognition systems are used. Systems based on computer vision in particular have the advantage that they allow an evaluation without affecting the normal behaviour of the animals. In recent years, methods based on deep learning have been introduced and have shown excellent results. Object and keypoint detector have frequently been used to detect individual animals. Despite promising results, bounding boxes and sparse keypoints do not trace the contours of the animals, resulting in a lot of information being lost. Therefore, this paper follows the relatively new approach of panoptic segmentation and aims at the pixel accurate segmentation of individual pigs. A framework consisting of a neural network for semantic segmentation as well as different network heads and postprocessing methods will be discussed. The method was tested on a data set of 1000 hand-labeled images created specifically for this experiment and achieves detection rates of around 95% (F1 score) despite disturbances such as occlusions and dirty lenses.

7 October 2021 in Sensors
Verified
Journal Article
Open access
PDF file
LSLars Schmarje
Lars Schmarje
JBJohannes Brünger
Johannes Brünger
MSMonty Santarossa
Monty Santarossa
SSSimon-Martin Schröder
Simon-Martin Schröder
RKRainer Kiko
Rainer Kiko
RKReinhard Koch
Reinhard Koch
Deep learning has been successfully applied to many classification problems including underwater challenges. However, a long-standing issue with deep learning is the need for large and consistently labeled datasets. Although current approaches in semi-supervised learning can decrease the required amount of annotated data by a factor of 10 or even more, this line of research still uses distinct classes. For underwater classification, and uncurated real-world datasets in general, clean class boundaries can often not be given due to a limited information content in the images and transitional stages of the depicted objects. This leads to different experts having different opinions and thus producing fuzzy labels which could also be considered ambiguous or divergent. We propose a novel framework for handling semi-supervised classifications of such fuzzy labels. It is based on the idea of overclustering to detect substructures in these fuzzy labels. We propose a novel loss to improve the overclustering capability of our framework and show the benefit of overclustering for fuzzy labels. We show that our framework is superior to previous state-of-the-art semi-supervised methods when applied to real-world plankton data with fuzzy labels. Moreover, we acquire 5 to 10% more consistent predictions of substructures.

1 September 2018 in Computers and Electronics in Agriculture
Verified
Journal Article
Closed access
JBJohannes Brünger
Johannes Brünger
ITImke Traulsen
Imke Traulsen
RKReinhard Koch
Reinhard Koch

11 July 2022 in Sensors
Verified
Journal Article
Open access
PDF file
Nina VolkmannNina Volkmann
Nina Volkmann
CZClaudius Zelenka
Claudius Zelenka
ADArchana Malavalli Devaraju
Archana Malavalli Devaraju
JBJohannes Brünger
Johannes Brünger
JSJenny Stracke
Jenny Stracke
RKReinhard Koch
Reinhard Koch
Injurious pecking against conspecifics is a serious problem in turkey husbandry. Bloody injuries act as a trigger mechanism to induce further pecking, and timely detection and intervention can prevent massive animal welfare impairments and costly losses. Thus, the overarching aim is to develop a camera-based system to monitor the flock and detect injuries using neural networks. In a preliminary study, images of turkeys were annotated by labelling potential injuries. These were used to train a network for injury detection. Here, we applied a keypoint detection model to provide more information on animal position and indicate injury location. Therefore, seven turkey keypoints were defined, and 244 images (showing 7660 birds) were manually annotated. Two state-of-the-art approaches for pose estimation were adjusted, and their results were compared. Subsequently, a better keypoint detection model (HRNet-W48) was combined with the segmentation model for injury detection. For example, individual injuries were classified using “near tail” or “near head” labels. Summarizing, the keypoint detection showed good results and could clearly differentiate between individual animals even in crowded situations.

9 September 2021 in Animals
Verified
Journal Article
Open access
PDF file
Nina VolkmannNina Volkmann
Nina Volkmann
JBJohannes Brünger
Johannes Brünger
JSJenny Stracke
Jenny Stracke
CZClaudius Zelenka
Claudius Zelenka
RKReinhard Koch
Reinhard Koch
Birgit SpindlerBirgit Spindler
Birgit Spindler
This study aimed to develop a camera-based system using artificial intelligence for automated detection of pecking injuries in turkeys. Videos were recorded and split into individual images for further processing. Using specifically developed software, the injuries visible on these images were marked by humans, and a neural network was trained with these annotations. Due to unacceptable agreement between the annotations of humans and the network, several work steps were initiated to improve the training data. First, a costly work step was used to create high-quality annotations (HQA) for which multiple observers evaluated already annotated injuries. Therefore, each labeled detection had to be validated by three observers before it was saved as “finished”, and for each image, all detections had to be verified three times. Then, a network was trained with these HQA to assist observers in annotating more data. Finally, the benefit of the work step generating HQA was tested, and it was shown that the value of the agreement between the annotations of humans and the network could be doubled. Although the system is not yet capable of ensuring adequate detection of pecking injuries, the study demonstrated the importance of such validation steps in order to obtain good training data.

21 May 2020 in arXiv
Verified
Preprint
Open access
PDF file
JBJohannes Brünger
Johannes Brünger
MGMaria Gentz
Maria Gentz
ITImke Traulsen
Imke Traulsen
RKReinhard Koch
Reinhard Koch
The behavioural research of pigs can be greatly simplified if automatic recognition systems are used. Especially systems based on computer vision have the advantage that they allow an evaluation without affecting the normal behaviour of the animals. In recent years, methods based on deep learning have been introduced and have shown pleasingly good results. Especially object and keypoint detectors have been used to detect the individual animals. Despite good results, bounding boxes and sparse keypoints do not trace the contours of the animals, resulting in a lot of information being lost. Therefore this work follows the relatively new definition of a panoptic segmentation and aims at the pixel accurate segmentation of the individual pigs. For this a framework of a neural network for semantic segmentation, different network heads and postprocessing methods is presented. With the resulting instance segmentation masks further information like the size or weight of the animals could be estimated. The method is tested on a specially created data set with 1000 hand-labeled images and achieves detection rates of around 95% (F1 Score) despite disturbances such as occlusions and dirty lenses.