Papers by Robert Sablatnig
Proceedings of the 31st AAPR/ …, Jan 1, 2007
A multi-spectral image acquisition system and a fully automatic image registration of ancient man... more A multi-spectral image acquisition system and a fully automatic image registration of ancient manuscripts are presented in this paper. Parchment sometimes contains two scripts, whereas the first script was erased. Multi-spectral imaging enhances the erased script and makes it visible to the human eye respectively. In this paper an image acquisition system is presented, that records UV reflectography as well as UV fluorescence images. Since the images, taken in varying spectral bands, are not aligned to each other, they have to be registered in order to be combined. The similarity of both images is computed by means of the normalized cross correlation, which is an area-based method. Afterwards the correlated images are aligned with each other, using the local weighted mean method. This paper contains images of manuscripts by which the registration process was tested.
Pattern Recognition, 2006. ICPR …, Jan 1, 2006
In this study we analyze texture and profile features of painted strokes in order to identify the... more In this study we analyze texture and profile features of painted strokes in order to identify the drawing media used for sketching underdrawings. Underdrawings are preliminary drawings on the panel prepared for paintings and are unseen in the finished work. Cameras working in the near infrared range allow the visualization of underdrawings. Due to the tiny width of the strokes we perform an alignment of the feature extraction windows in order to obtain a major content of the stroke texture. The method is tested on strokes applied on test panels and underdrawing strokes in IR images of medieval paintings.
Proceedings of IAPR …, Jan 1, 2007
This paper presents uncertainty propagation in landmark based position estimation methods. Analys... more This paper presents uncertainty propagation in landmark based position estimation methods. Analysis of two methods has been carried out where robot position is estimated by detecting one or two globally distinct features using a pivoted stereo vision system. We make a basic assumption about error in estimating point features in camera images and propagate it into robot position estimate using first order approximation of non-linear functions. Simulation results illustrate the performance of the method.
… , 2006. ICPR 2006. …, Jan 1, 2006
This paper presents a method for the fully automatic surveying of cutaneous hemangiomas by means ... more This paper presents a method for the fully automatic surveying of cutaneous hemangiomas by means of a hemangioma segmentation and a ruler visible in the images. The algorithm computes the spatial resolution of an image. Hemangioma segmentation is accomplished by a single-layer perceptron classification by means of pixel color features. The algorithm was evaluated on a set of 120 images. It achieves satisfactory results on images with clearly visible, saturated hemangiomas.
Image Analysis and …, Jan 1, 2009
Abstract. This paper presents implementation of a memory efficient all integer line feature extra... more Abstract. This paper presents implementation of a memory efficient all integer line feature extraction algorithm for tiny autonomous mobile robot with limited on-chip memory. A circular buffer is used to bring image data from off chip to the on chip memory of the DSP for detecting edges. Afterwards a gradient based Hough transform is used to group collinear pixels which are processed to detect end points and length of the line segments. Approximation of the two dimensional Hough parameter space using a one dimensional ...
Robust Vision for Industrial Applications, Proc. of …
… of the 9th IAPR International Workshop …, Jan 1, 2010
Abstract Document analysis is done to analyze entire forms (eg intelligent form analysis, table d... more Abstract Document analysis is done to analyze entire forms (eg intelligent form analysis, table detection) or to describe the layout/structure of a document. In this paper document analysis is applied to snippets of torn documents to calculate features that can be used for ...
Document Analysis and …, Jan 1, 2011
Abstract The proposed binarization algorithm uses a scale space to avoid the estimation of script... more Abstract The proposed binarization algorithm uses a scale space to avoid the estimation of script size dependent parameters. Due to the continous smoothing from finer to coarse scales, noise such as background clutter is suppressed since coarse scales characterize ...
Forum Archaeologiae-Zeitschrift für klassische …, Jan 1, 2005
[Zurück]. @article{TUW-139942, author = {Mara, Hubert and Sablatnig, Robert}, title = {3D-Vision ... more [Zurück]. @article{TUW-139942, author = {Mara, Hubert and Sablatnig, Robert}, title = {3D-Vision Applied in Archaeology}, journal = {Forum Archaeologiae}, year = {2005}, volume = {http://farch.net}, note = {eingeladen} } Erstellt aus der Publikationsdatenbank der Technischen Universität Wien.
Progress in Pattern …, Jan 1, 2003
An algorithm for the automatic identification of drawing tools based on the appearance of the str... more An algorithm for the automatic identification of drawing tools based on the appearance of the stroke boundary is presented. The purpose of this stroke analysis is the determination of drawing tools in underdrawings -the basic concept of an artist -in ancient panel paintings. This information allows significant support for a systematic stylistic approach in the analysis of paintings. Up to now the identification of drawing tools is performed by an expert visually. Our tool will support the expert to investigate larger numbers of underdrawings, provides objective and reproducible information and simplifies comparison of different underdrawings. Stroke analysis in paintings is related to the extraction and recognition of handwritings, therefore similar techniques to stroke analysis are used. Following the segmentation, the approximation of the stroke boundary is done by active contours with different parameters. Deviations between a rigid and elastic "snake" are used as descriptive features for differentiation between drawing tools. Results of the algorithm are presented for sets of three different types of strokes.
Intelligent Solutions …, Jan 1, 2006
Estimation of objects in a 3D space is a fundamental problem in computer vision and robotics. Thi... more Estimation of objects in a 3D space is a fundamental problem in computer vision and robotics. This paper describes an algorithm and its implementation for a vision module as a sensor of a biped robot (YABIRO). The embedded vision sensor is able to estimate the position of objects like spheres in 3D space. Objects are defined with their size and color in a model. The vision sensor detects the positions or at least the directions to the objects and stores them in a history. The algorithm includes a new voting system for detected objects, based on how trustable the detection was, and a new edge filter to terminate edges on the circle border for the circle detection. The systems frame rate depends on the area of interest and lies between 5 Hz and 20 Hz. With a mechanical size of 36x32mm it is smaller than a matchbox.
Interfacing the Past: Computer Applications and …, Jan 1, 1996
Image Analysis, Jan 1, 2005
The recognition of painted strokes is an important step in analyzing underdrawings in infrared re... more The recognition of painted strokes is an important step in analyzing underdrawings in infrared reflectogramms. But even for art experts, it is difficult to recognize all drawing tools and materials used for the creation of the strokes. Thus the use of computer-aided imaging ...
… with Non-Traditional Sensors, Proc. of …, Jan 1, 2002
An algorithm for the automatic construction of a 3d model of archaeological vessels using two dif... more An algorithm for the automatic construction of a 3d model of archaeological vessels using two different 3d algorithms is presented. In archeology the determination of the exact volume of arbitrary vessels is of importance since this provides information about the manufacturer and the usage of the vessel. To acquire the 3d shape of objects with handles is complicated, since occlusions of the object's surface are introduced by the handle and can only be resolved by taking multiple views. Therefore, the 3d reconstruction is based on a sequence of images of the object taken from different viewpoints with two different algorithms; shape from silhouette and shape from structured light. The output of both algorithms are then used to construct a single 3d model. Results of the algorithm developed are presented for both synthetic and real input images.
Frontiers in Handwriting …, Jan 1, 2010
Abstract An approach for the detection of decorative elements-such as initials and headlines-and ... more Abstract An approach for the detection of decorative elements-such as initials and headlines-and text regions, focused on ancient manuscripts, is presented. Due to their age, ancient manuscripts suffer from degradation and staining as well as ink is faded-out over the time. ...
Conference on Electronic Visualisation and the Arts ( …, Jan 1, 2008
Three-dimensional imaging in …, Jan 1, 2002
At excavations a large number of sherds of archaeological pottery is found. Since the documentati... more At excavations a large number of sherds of archaeological pottery is found. Since the documentation and administration of these fragments represent a temporal and personnel effort, we construct a computer aided documentation system for archaeological fragments to form the basis for a subsequent semiautomatic classification and reconstruction. The main technical goal of this project is to perform an automated classification based on the profile section of the oriented object, which is the cross-section of the fragment in the direction of the rotational axis of symmetry. To achieve the profile, a 3d-representation of the object is necessary. The final aim is to provide a tool that helps archaeologists in their archivation process. This paper gives an overview about an automated archivation process and 3d-acquisition with respect to archaeological requirements.
Czech Pattern Recognition Workshop'97, Proc. of ( …, Jan 1, 1997
This work aims to show a systematic automated visual inspection concept that speeds up the develo... more This work aims to show a systematic automated visual inspection concept that speeds up the development of such systems by providing a software reuse and setup concept. A new, highly adaptable concept for visual inspection separates the detection of primitives from the modelbased analysis process. This separation is reached by defining a general analysis graph for inspection, containing detail relations that represent detection algorithms. Together with an object specific description, defined in a so called description language, the analysis graph is instantiated. Existing pattern recognition software is re-used in the detection stage and therefore the use of any detection algorithm is possible without changing the analysis. The flexible visual inspection concept is based on a systematic approach, that is able to increase the degree of flexibility and thus to decrease the set-up costs taking into account different type of data, positioning, occlusions and tolerances. The concept can be seen as "recipe" for solving industrial applications, stating at which stage, which kind of decisions have to be made. The visual inspection of analog display measuring instruments serves as a demonstration of this concept. The flexibility of the concept is demonstrated by testing the analysis process with the description of two instruments (a hygrometer and a clock), which is performed by adapting the analysis graph but without changing the detection algorithms. Since the detection is represented as detail relation in the analysis graph, a change of the detection algorithm is possible without changing the overall analysis. The separation of detection and analysis therefore ensures, that any existing pattern recognition software can be re-used.
14th International Conference on Virtual Systems and …, Jan 1, 2008
Proc. of Intl. Workshop on …, Jan 1, 2002
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Papers by Robert Sablatnig