On the Objectivity of the Objective Function—Problems with Unsupervised Segmentation Evaluation Based on Global Score and a Possible Remedy

Image segmentation is a crucial stage at the very beginning of many geographic object-based image analysis (GEOBIA) workflows. While segmentation quality is generally deemed of great importance, selecting adequate tuning parameters for a segmentation algorithm can be tedious and subjective. Procedur...

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Main Authors: Sebastian Böck, Markus Immitzer, Clement Atzberger
Format: Article
Language:English
Published: MDPI AG 2017-07-01
Series:Remote Sensing
Subjects:
Online Access:https://www.mdpi.com/2072-4292/9/8/769
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author Sebastian Böck
Markus Immitzer
Clement Atzberger
author_facet Sebastian Böck
Markus Immitzer
Clement Atzberger
author_sort Sebastian Böck
collection DOAJ
description Image segmentation is a crucial stage at the very beginning of many geographic object-based image analysis (GEOBIA) workflows. While segmentation quality is generally deemed of great importance, selecting adequate tuning parameters for a segmentation algorithm can be tedious and subjective. Procedures to automatically choose parameters of a segmentation algorithm are meant to make the process objective and reproducible. One of those approaches, and perhaps the most frequently used unsupervised parameter optimization method in the context of GEOBIA is called the objective function, also known as Global Score. Unfortunately, the method exhibits a hitherto widely neglected, yet severe source of instability, which makes quality rankings inconsistent. We demonstrate the issue in detail and propose a modification of the Global Score to mitigate the problem. This hopefully serves as a starting point to spark further development of the popular approach.
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spelling doaj.art-70056b2607424f8cb394cc1fd8b471b02022-12-22T04:06:23ZengMDPI AGRemote Sensing2072-42922017-07-019876910.3390/rs9080769rs9080769On the Objectivity of the Objective Function—Problems with Unsupervised Segmentation Evaluation Based on Global Score and a Possible RemedySebastian Böck0Markus Immitzer1Clement Atzberger2Institute of Surveying, Remote Sensing and Land Information (IVFL), University of Natural Resources and Life Sciences, Vienna (BOKU), Peter Jordan Strasse 82, 1190 Vienna, AustriaInstitute of Surveying, Remote Sensing and Land Information (IVFL), University of Natural Resources and Life Sciences, Vienna (BOKU), Peter Jordan Strasse 82, 1190 Vienna, AustriaInstitute of Surveying, Remote Sensing and Land Information (IVFL), University of Natural Resources and Life Sciences, Vienna (BOKU), Peter Jordan Strasse 82, 1190 Vienna, AustriaImage segmentation is a crucial stage at the very beginning of many geographic object-based image analysis (GEOBIA) workflows. While segmentation quality is generally deemed of great importance, selecting adequate tuning parameters for a segmentation algorithm can be tedious and subjective. Procedures to automatically choose parameters of a segmentation algorithm are meant to make the process objective and reproducible. One of those approaches, and perhaps the most frequently used unsupervised parameter optimization method in the context of GEOBIA is called the objective function, also known as Global Score. Unfortunately, the method exhibits a hitherto widely neglected, yet severe source of instability, which makes quality rankings inconsistent. We demonstrate the issue in detail and propose a modification of the Global Score to mitigate the problem. This hopefully serves as a starting point to spark further development of the popular approach.https://www.mdpi.com/2072-4292/9/8/769segmentation evaluationGEOBIAparameter optimizationGlobal Score
spellingShingle Sebastian Böck
Markus Immitzer
Clement Atzberger
On the Objectivity of the Objective Function—Problems with Unsupervised Segmentation Evaluation Based on Global Score and a Possible Remedy
Remote Sensing
segmentation evaluation
GEOBIA
parameter optimization
Global Score
title On the Objectivity of the Objective Function—Problems with Unsupervised Segmentation Evaluation Based on Global Score and a Possible Remedy
title_full On the Objectivity of the Objective Function—Problems with Unsupervised Segmentation Evaluation Based on Global Score and a Possible Remedy
title_fullStr On the Objectivity of the Objective Function—Problems with Unsupervised Segmentation Evaluation Based on Global Score and a Possible Remedy
title_full_unstemmed On the Objectivity of the Objective Function—Problems with Unsupervised Segmentation Evaluation Based on Global Score and a Possible Remedy
title_short On the Objectivity of the Objective Function—Problems with Unsupervised Segmentation Evaluation Based on Global Score and a Possible Remedy
title_sort on the objectivity of the objective function problems with unsupervised segmentation evaluation based on global score and a possible remedy
topic segmentation evaluation
GEOBIA
parameter optimization
Global Score
url https://www.mdpi.com/2072-4292/9/8/769
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