- Silvretta (3)
- digital image analysis (2)
- remote sensing (2)
- texture segmentation (2)
- Archäologie (1)
- Archäologische Prospektion (1)
- Climate change ; human impact ; Silvretta Massif ; human adaption ; Alpine Space (1)
- Fernerkundung (1)
- Silvrettagruppe ; Klimaänderung ; Holozän ; Online-Publikation (1)
- Texture detection; Feature detection; Isolated structures; Alternating morphological filters (1)
- Human Activity in the Silvretta Massif and Climatic Developments throughout the Holocene (2012)
- Human Activity in the Silvretta Massif and Climatic Developments throughout the Holocene
- Am Boden, aus der Luft, aus dem All : Prospektion archäologischer Fundstellen in der Silvretta (2012)
- Die archäologische Erforschung der Silvretta hat zur Entdeckung zahlreicher bisher unbekannter Fundstellen geführt, deren Untersuchung tiefe Einblicke in die Geschichte dieser Region erlaubt. Doch woher wissen Archäologen, wo sie etwas finden? Die Suche und Identifizierung von archäologischen Fundstellen, die sogenannte Prospektion, ist ein wichtiger Aspekt der Arbeiten in der Silvretta. Neben traditionellen Methoden kommen dabei auch hochmoderne Verfahren wie unbemannte Fluggeräte oder die teilautomatisierte Auswertung von Satellitenbildern zum Einsatz.
- Von Bildern zu Bühnen: Die Geoglyphen von Palpa und Nasca (Süd-Peru) in ihrem räumlichen und sozialen Kontext (2012)
- Morphological operators for segmentation of high contrast textured regions in remotely sensed imagery (2012)
- We develop a transformation based on morphological filters that measures the contrast of image texture. This ransforma tion is proportional to texture contrast, but insensitive to its specific type. Though the transformation provides a high response in textured areas, it suppresses individual high contrast features that stand apart from textured areas. It can serve as an effective texture descriptor for unsupervised or supervised segmentation of textured regions, provides high accuracy of localization and does not involve heavy computations. The method is robust to variations of illumination and works on different types of images without needing to be tuned. The only parameter is a scale related parameter. We illustrate the use of the proposed method on satellite and aerial images.
- Erster Workshop der Arbeitsgemeinschaft Computeranwendungen und quantitative Methoden in der Archäologie (AG CAA) am 22. und 23. Januar 2010 in Bonn (2012)
- Texture segmentation as a first step towards archaeological object detection in high-resolution satellite images of the Silvretta Alps (2013)
- Detection of texture and isolated features using alternating morphological filters (2013)
- Recently, we introduced a morphological texture contrast (MTC) operator that allows detection of textural and non-texture regions in images. In this paper we provide comparison of the MTC with other available techniques. We show that, in contrast to other approaches, the MTC discriminates between texture details and isolated features, and does not extend borders of texture regions. Using the ideas underlying the MTC operator, we develop a complementary operator called morphological feature contrast (MFC) that allows extraction of isolated features while not being confused by texture details. We illustrate an application of the MFC operator for extraction of isolated bjects such as individual trees or buildings that should be distinguished from forests or urban centers. We furthermore provide an example of how this operator can be used for detection of isolated linear structures. We also derive an extended version of the MFC that works with vector-valued images.
- Silvretta Historica: Satellite-assisted Archaeological Survey in an Alpine Environment (2013)
- In this paper we report on a new archaeological project in the central Alps, titled Silvretta Historica, in which satellite-assisted archaeological surveying is intended to play a key role. Following an overview of the Silvretta study area on the Swiss-Austrian border and its archaeology, we present the first results of recent archaeological fieldwork focussing on the remains of prehistoric alpine pasture economy or Alpwirtschaft. We then continue to discuss why spectral and geometric analysis of high-resolution satellite images are considered a promising method to assist archaeological survey in a high alpine environment.
- Automated search for livestock enclosures of rectangular shape in remotely sensed imagery (2013)
- We introduce an approach for the detection of approximately rectangular structures in gray scale images. Our research is motivated by the Silvretta Historica project that aims at automated detection of remains of livestock enclosures in remotely sensed images of alpine regions. The approach allows detection of enclosures with linear sides of various sizes and proportions. It is robust to incomplete or fragmented rectangles and tolerates deviations from a perfect rectangular shape. Morphological operators are used to extract linear features. They are grouped into parameterized linear segments by means of a local Hough transform. To identify appropriate configurations of linear segments we define convexity and angle constraints. Configurations meeting these constraints are rated by a proposed rectangularity measure that discards overly fragmented configurations and configurations with more than one side completely missing. The search for appropriate configurations is efficiently performed on a graph. Its nodes represent linear segments and edges encode the above constraints. We tested our approach on a set of aerial and GeoEye-1 satellite images of 0.5m resolution that contain ruined livestock enclosures of approximately rectangular shape. The approach showed encouraging results in finding configurations of linear segments originating from the objects of our interest.