portrait

Dr. Amir Semmo


Interactive graphics engineer and post-doctoral researcher in the Computer Graphics Systems group at the Hasso Plattner Institute / University of Potsdam, Germany.

Specialized in real-time rendering and shading, non-photorealistic rendering, computational aesthetics / cartographic design, and geovisualization.

May 2017

Our paper “Neural Style Transfer: A Paradigm Shift for Image-based Artistic Rendering?” has been accepted as a contribution to the 2017 Symposium on Non-Photorealistic Animation and Rendering (NPAR, part of Expressive). We will also present the mobile app “Pictory: Combining Neural Style Transfer and Image Filtering” at SIGGRAPH 2017 Appy Hour.

December 2016

We also presented the demo “BeCasso: Artistic Image Processing and Editing on Mobile Devices” at the SIGGRAPH Asia 2016 Symposium on Mobile Graphics and Interactive Applications. The demo received a Best Demo Award.

December 2016

We presented the paper “Interactive Image Filtering with Multiple Levels-of-Control on Mobile Devices” at the SIGGRAPH Asia 2016 Symposium on Mobile Graphics and Interactive Applications.

November 2016

I successfully defended my doctoral thesis on the “Design and Implementation of Non-Photorealistic Rendering Techniques for 3D Geospatial Data”.

July 2016

We also presented the poster “Interactive Multi-scale Oil Paint Filtering on Mobile Devices” at SIGGRAPH 2016.

July 2016

We presented the demo “BeCasso: Image Stylization by Interactive Oil Paint Filtering on Mobile Devices” at SIGGRAPH 2016 Appy Hour.

May 2016

We presented the poster “Interactive Oil Paint Filtering On Mobile Devices” at Expressive 2016.

January 2016

Our journal article on “Image Stylization by Interactive Oil Paint Filtering” was published in Computers & Graphics.

Design and Implementation of Non-Photorealistic Rendering Techniques for 3D Geospatial Data

Amir Semmo
Doctoral Thesis, Hasso Plattner Institute at the University of Potsdam 2016

This thesis proposes non-photorealistic rendering techniques that enable both the computation and selection of the abstraction level of 3D geospatial model contents according to user interaction and dynamically changing thematic information. To achieve this goal, the techniques integrate with hardware-accelerated rendering pipelines using shader technologies of graphics processing units for real-time image synthesis. The techniques employ principles of artistic rendering, cartographic generalization, and 3D semiotics—unlike photorealistic rendering—to synthesize illustrative renditions of geospatial feature type entities such as water surfaces, buildings, and infrastructure networks. In addition, this thesis contributes a generic system that enables to integrate different graphic styles—photorealistic and non-photorealistic—and provide their seamless transition according to user tasks, camera view, and image resolution.

URN, Thesis (PDF)

Pictory: Combining Neural Style Transfer and Image Filtering

Amir Semmo, Matthias Trapp, Jürgen Döllner, and Mandy Klingbeil,
ACM SIGGRAPH Appy Hour 2017

This work presents Pictory, a mobile app that empowers users to transform photos into artistic renditions by using a combination of neural style transfer with user-controlled state-of-the-art nonlinear image filtering. The combined approach features merits of both artistic rendering paradigms: deep convolutional neural networks can be used to transfer style characteristics at a global scale, while image filtering is able to simulate phenomena of artistic media at a local scale. Thereby, the proposed app implements an interactive two-stage process: first, style presets based on pre-trained feed-forward neural networks are applied using GPU-accelerated compute shaders to obtain initial results. Second, the intermediate output is stylized via oil paint, watercolor, or toon filtering to inject characteristics of traditional painting media such as pigment dispersion (watercolor) as well as soft color blendings (oil paint), and to filter artifacts such as fine-scale noise. Finally, on-screen painting facilitates pixel-precise creative control over the filtering stage, e. g., to vary the brush and color transfer, while joint bilateral upsampling enables outputs at full image resolution suited for printing on real canvas.

BibTeX, DOI, Paper (PDF)

@inproceedings{STDKD17,
  author = { Semmo, Amir and Trapp, Matthias and D{\"o}llner, J{\"u}rgen and Klingbeil, Mandy },
  title = { Pictory: Combining Neural Style Transfer and Image Filtering },
  year = { 2017 },
  series = { Proceedings SIGGRAPH Appy Hour },
  month = { 8 },
  publisher = { ACM },
  address = { New York },
  doi = { 10.1145/3098900.3098906 },
  note = { To appear },
}

BeCasso: Artistic Image Processing and Editing on Mobile Devices

Sebastian Pasewaldt, Amir Semmo, Jürgen Döllner, and Frank Schlegel,
ACM SIGGRAPH Asia Symposium on Mobile Graphics and Interactive Applications (Demo) 2016

BeCasso is a mobile app that enables users to transform photos into high-quality, high-resolution non-photorealistic renditions, such as oil and watercolor paintings, cartoons, and colored pencil drawings, which are inspired by real-world paintings or drawing techniques. In contrast to neuronal network and physically-based approaches, the app employs state-of-the-art nonlinear image filtering. For example, oil paint and cartoon effects are based on smoothed structure information to interactively synthesize renderings with soft color transitions. BeCasso empowers users to easily create aesthetic renderings by implementing a two-fold strategy: First, it provides parameter presets that may serve as a starting point for a custom stylization based on global parameter adjustments. Thereby, users can obtain initial renditions that may be fine-tuned afterwards. Second, it enables local style adjustments: using on-screen painting metaphors, users are able to locally adjust different stylization features, e.g., to vary the level of abstraction, pen, brush and stroke direction or the contour lines. In this way, the app provides tools for both higher-level interaction and low-level control to serve the different needs of non-experts and digital artists.

DOI, Paper (PDF)

Interactive Multi-scale Oil Paint Filtering on Mobile Devices

Amir Semmo, Mattias Trapp, Tobias Dürschmid, Jürgen Döllner, and Sebastian Pasewaldt,
ACM SIGGRAPH Posters 2016

This work presents an interactive mobile implementation of a filter that transforms images into an oil paint look. At this, a multi-scale approach that processes image pyramids is introduced that uses flow-based joint bilateral upsampling to achieve deliberate levels of abstraction at multiple scales and interactive frame rates. The approach facilitates the implementation of interactive tools that adjust the appearance of filtering effects at run-time, which is demonstrated by an on-screen painting interface for per-pixel parameterization that fosters the casual creativity of non-artists.

BibTeX, DOI, Paper (PDF)

@misc{STDDP2016,
  author = { Semmo, Amir and Trapp, Matthias and D{\"u}rschmid, Tobias and D{\"o}llner, J{\"u}rgen and Pasewaldt, Sebastian },
  title = { Interactive Multi-scale Oil Paint Filtering on Mobile Devices },
  booktitle = { SIGGRAPH Posters },
  year = { 2016 },
  doi = { 10.1145/2945078.2945120 }
}

Interactive Oil Paint Filtering On Mobile Devices

Amir Semmo, Matthias Trapp, Sebastian Pasewaldt, and Jürgen Döllner,
Expressive Poster Session 2016

Image stylization enjoys a growing popularity on mobile devices to foster casual creativity. However, the implementation and provision of high-quality image filters for artistic rendering is still faced by the inherent limitations of mobile graphics hardware such as computing power and memory resources. This work presents a mobile implementation of a filter that transforms images into an oil paint look, thereby highlighting concepts and techniques on how to perform multi-stage nonlinear image filtering on mobile devices. The proposed implementation is based on OpenGL ES and the OpenGL ES shading language, and supports on-screen painting to interactively adjust the appearance in local image regions, e.g., to vary the level of abstraction, brush, and stroke direction. Evaluations of the implementation indicate interactive performance and results that are of similar aesthetic quality than its original desktop variant.

BibTeX, DOI, Paper (PDF)

@misc{STPD2016,
  author = { Semmo, Amir and Trapp, Matthias and Pasewaldt, Sebastian and D{\"o}llner, J{\"u}rgen },
  title = { Interactive Oil Paint Filtering On Mobile Devices },
  booktitle = { Expressive Poster Session },
  year = { 2016 }
}

Image Stylization by Oil Paint Filtering using Color Palettes

Amir Semmo, Daniel Limberger, Jan Eric Kyprianidis, and Jürgen Döllner,
Proceedings International Symposium on Computational Aesthetics in Graphics, Visualization, and Imaging (CAe) 2015

This paper presents an approach for transforming images into an oil paint look. To this end, a color quantization scheme is proposed that performs feature-aware recolorization using the dominant colors of the input image. In addition, an approach for real-time computation of paint textures is presented that builds on the smoothed structure adapted to the main feature contours of the quantized image. Our stylization technique leads to homogeneous outputs in the color domain and enables creative control over the visual output, such as color adjustments and per-pixel parametrizations by means of interactive painting.

BibTeX, Paper (PDF), Filter Results (Images / ZIP, 191 MiB)

@inproceedings{SLKD14,
  author = { Semmo, Amir and Limberger, Daniel and Kyprianidis, Jan Eric and D{\"o}llner, J{\"u}rgen },
  title = { Image Stylization by Oil Paint Filtering using Color Palettes },
  booktitle = { Proceedings International Symposium on Computational Aesthetics in Graphics, Visualization, and Imaging (CAe) },
  year = { 2015 },
  pages = { 149--158 },
  month = { 6 },
  doi = { 10.2312/exp.20151188 }
}

Interactive Rendering and Stylization of Transportation Networks Using Distance Fields

Matthias Trapp, Amir Semmo, and Jürgen Döllner,
Proceedings of the 10th International Conference on Computer Graphics Theory and Applications (GRAPP) 2015

Transportation networks, such as streets, railroads or metro systems, constitute primary elements in cartography for reckoning and navigation. In recent years, they have become an increasingly important part of 3D virtual environments for the interactive analysis and communication of complex hierarchical information, for example in routing, logistics optimization, and disaster management. A variety of rendering techniques have been proposed that deal with integrating transportation networks within these environments, but have so far neglected the many challenges of an interactive design process to adapt their spatial and thematic granularity (i.e., level-of-detail and level-of-abstraction) according to a user's context. This paper presents an efficient real-time rendering technique for the view-dependent rendering of geometrically complex transportation networks within 3D virtual environments. Our technique is based on distance fields using deferred texturing that shifts the design process to the shading stage for real-time stylization. We demonstrate and discuss our approach by means of street networks using cartographic design principles for context-aware stylization, including view-dependent scaling for clutter reduction, contour-lining to provide figure-ground, handling of street crossings via shading-based blending, and task-dependent colorization. Finally, we present potential usage scenarios and applications together with a performance evaluation of our implementation.

BibTeX, Paper (PDF)

@inproceedings{TSD2015,
  author = { Trapp, Matthias and Semmo, Amir and D{\"o}llner, J{\"u}rgen },
  title = { Interactive Rendering and Stylization of Transportation Networks Using Distance Fields },
  booktitle = { Proceedings of the 10th International Conference on Computer Graphics Theory and Applications (GRAPP) },
  year = { 2015 }
}

An Interaction Framework for Level-of-Abstraction Visualization of 3D Geovirtual Environments

Amir Semmo and Jürgen Döllner
Proceedings 2nd ACM SIGSPATIAL Workshop on MapInteraction 2014

3D geovirtual environments constitute effective media for the analysis and communication of complex geospatial data. Today, these environments are often visualized using static graphical variants (e.g., 2D maps, 3D photorealistic) from which a user is able to choose from. To serve the different interests of users in specific information, however, the spatial and thematic granularity at which model contents are represented (i.e., level of abstraction) should be dynamically adapted to the user's context, which requires specialized interaction techniques for parameterization. In this work, we present a framework that enables interaction interfaces to parameterize the level-of-abstraction visualization according to spatial, semantic, and thematic data. The framework is implemented in a visualization system that provides image-based rendering techniques for context-aware abstraction and highlighting. Using touch and natural language interfaces, we demonstrate its versatile application to geospatial tasks, including exploration, navigation, and orientation.

BibTeX, Paper (PDF)

@inproceedings{SD2014_3,
  author = { Semmo, Amir and D{\"o}llner, J{\"u}rgen },
  title = { An Interaction Framework for Level-of-Abstraction Visualization of 3D Geovirtual Environments },
  booktitle = { Proceedings 2nd ACM SIGSPATIAL Workshop on MapInteraction (MapInteract) },
  year = { 2014 },
  month = { 11 }
}

Oil Paint Filtering Using Color Palettes For Colorization

Amir Semmo and Jürgen Döllner
Expressive Poster Session 2014

We present a novel technique for oil paint filtering that uses color palettes for colorization. First, dominant feature-aware colors are derived from the input image via entropy-based metrics. Seed pixels are then determined and propagated to the remaining pixels by adopting the optimization framework of Levin et al. [2004] for feature-aware colorization. Finally, the quantized output is combined with flow-based highlights and contour lines to simulate paint texture. Our technique leads to homogeneous outputs in the color domain and enables interactive control over color definitions.

BibTeX, Paper (PDF)

@misc{SD2014_2,
  author = { Semmo, Amir and D{\"o}llner, J{\"u}rgen },
  title = { Oil Paint Filtering Using Color Palettes For Colorization },
  booktitle = { Expressive Poster Session },
  year = { 2014 }
}

Image Filtering for Interactive Level-of-Abstraction Visualization of 3D Scenes

Amir Semmo and Jürgen Döllner
Proceedings International Symposium on Computational Aesthetics in Graphics, Visualization, and Imaging (CAe) 2014

Texture mapping is a key technology in computer graphics for visual design of rendered 3D scenes. An effective information transfer of surface properties, encoded by textures, however, depends significantly on how important information is highlighted and cognitively processed by the user in an application context. Edge-preserving image filtering is a promising approach to address this concern while preserving global salient structures. Much research has focused on applying image filters in a post-process stage to foster an artistically stylized rendering, but these approaches are generally not able to preserve depth cues important for 3D visualization (e.g., texture gradient). To this end, filtering that processes texture data coherently with respect to linear perspective and spatial relationships is required. In this work, we present a system that enables to process textured 3D scenes with perspective coherence by arbitrary image filters. We propose decoupled deferred texturing with (1) caching strategies to interactively perform image filtering prior to texture mapping, and (2) for each mipmap level separately to enable a progressive level of abstraction. We demonstrate the potentials of our methods on several applications, including illustrative visualization, focus+context visualization, geometric detail removal, and depth of field. Our system supports frame-to-frame coherence, order-independent transparency, multitexturing, and content-based filtering.

BibTeX, DOI, Paper (PDF), Additional Material (PDF), Video (Youtube)

@inproceedings{SD14,
  author = { Semmo, Amir and D{\"o}llner, J{\"u}rgen },
  title = { Image Filtering for Interactive Level-of-Abstraction Visualization of 3D Scenes },
  booktitle = { Proceedings International Symposium on Computational Aesthetics in Graphics, Visualization, and Imaging (CAe) },
  year = { 2014 },
  pages = { 5--14 },
  month = { 8 },
  doi = { 10.1145/2630099.2630101 }
}

Interactive Projective Texturing for Non-Photorealistic Shading of Technical 3D Models

Roland Lux, Matthias Trapp, Amir Semmo, and Jürgen Döllner,
Proceedings of 11th Theory and Practice of Computer Graphics 2013 Conference (TP.CG) 2013

This paper presents a novel interactive rendering technique for creating and editing shadings for man-made objects in technical 3D visualizations. In contrast to shading approaches that use intensities computed based on surface normals (e.g., Phong, Gooch, Toon shading), the presented approach uses one-dimensional gradient textures, which can be parametrized and interactively manipulated based on per-object bounding volume approximations. The fully hardware-accelerated rendering technique is based on projective texture mapping and customizable intensity transfer functions. A provided performance evaluation shows comparable results to traditional normal-based shading approaches. The work also introduce simple direct-manipulation metaphors that enables interactive user control of the gradient texture alignment and intensity transfer functions.

BibTeX, Vido (Youtube), Paper (PDF)

@inproceedings{LTSD13,
  author = { Lux, Roland and Trapp, Matthias and Semmo, Amir and D{\"o}llner, J{\"u}rgen },
  title = { Interactive Projective Texturing for Non-Photorealistic Shading of Technical 3D Models },
  booktitle = { Proceedings of 11th Theory and Practice of Computer Graphics Conference (TP.CG) },
  year = { 2013 },
  editor = { Silvester Czanner, Wen Tang },
  pages = { 101--108 },
  month = { 9 },
  publisher = { The Eurographics Association },
  isbn = { 978-3-905673-98-2 }
}

Towards Comprehensible Digital 3D Maps

Sebastian Pasewaldt, Amir Semmo, Matthias Trapp, and Jürgen Döllner,
Proceedings Service-Oriented Mapping (SOMAP) 2012

Digital mapping services have become fundamental tools in economy and society to provide domain experts and non-experts with customized, multi-layered map contents. In particular because of the continuous advancements in the acquisition, provision, and visualization of virtual 3D city and landscape models, 3D mapping services, today, represent key components to a growing number of applications, like car navigation, education, or disaster management. However, current systems and applications providing digital 3D maps are faced by drawbacks and limitations, such as occlusion, visual clutter, or insufficient use of screen space, that impact an effective comprehension of geoinformation. To this end, cartographers and computer graphics engineers developed design guidelines, rendering and visualization techniques that aim to increase the effectiveness and expressiveness of digital 3D maps, but whose seamless combination has yet to be achieved. This work discusses potentials of digital 3D maps that are based on combining cartography-oriented rendering techniques and multi-perspective views. For this purpose, a classification of cartographic design principles, visualization techniques, as well as suitable combinations are identified that aid comprehension of digital 3D maps. According to this classification, a prototypical implementation demonstrates the benefits of multi-perspective and non-photorealistic rendering techniques for visualization of 3D map contents. In particular, it enables (1) a seamless combination of cartography-oriented and photorealistic graphic styles while (2) increasing screen-space utilization, and (3) simultaneously directing a viewer’s gaze to important or prioritized information.

BibTeX, Paper (PDF), Slides (PDF)

@inproceedings{PSTD12,
  author = { Pasewaldt, Sebastian and Semmo, Amir and Trapp, Matthias and D{\"o}llner, J{\"u}rgen },
  title = { Towards Comprehensible Digital 3D Maps },
  booktitle = { Service-Oriented Mapping (SOMAP) },
  year = { 2012 },
  editor = { Markus Jobst },
  pages = { 261--276 },
  month = { 11 },
  organization = { International Cartographic Association },
  publisher = { Jobstmedia Management Verlag, Wien }
}

Colonia 3D - Communication of Virtual 3D Reconstructions in Public Spaces

Matthias Trapp, Amir Semmo, Rafael Pokorski, Claus-Daniel Herrmann, Jürgen Döllner, Michael Eichhorn, and Michael Heinzelmann,
International Journal of Heritage in the Digital Era (IJHDE) 2012

The communication of cultural heritage in public spaces such as museums or exhibitions, gain more and more importance during the last years. The possibilities of interactive 3D applications open a new degree of freedom beyond the mere presentation of static visualizations, such as pre-produced video or image data. A user is now able to directly interact with 3D virtual environments that enable the depiction and exploration of digital cultural heritage artifacts in real-time. However, such technology requires concepts and strategies for guiding a user throughout these scenarios, since varying levels of experiences within interactive media can be assumed. This paper presents a concept as well as implementation for communication of digital cultural heritage in public spaces, by example of the project Roman Cologne. It describes the results achieved by an interdisciplinary team of archaeologists, designers, and computer graphics engineers with the aim to virtually reconstruct an interactive high-detail 3D city model of Roman Cologne.

BibTeX, DOI, Paper (PDF)

@article{TSPHDEH12,
  author = { Trapp, Matthias and Semmo, Amir and Pokorski, Rafael and Herrmann,
	Claus-Daniel and D{\"o}llner, J{\"u}rgen and Eichhorn, Michael and Heinzelmann, Michael },
  title = { Colonia 3D - Communication of Virtual 3D Reconstructions in Public Spaces },
  journal = { International Journal of Heritage in the Digital Era (IJHDE) },
  year = { 2012 },
  volume = { 1 },
  pages = { 45--74 },
  number = { 1 },
  month = { 1 },
  doi = { 10.1260/2047-4970.1.1.45 },
  editor = { Marinos Ioannides },
  publisher = { Multi-Science Publishing }
}

Colonia3D

Matthias Trapp, Amir Semmo, and Jürgen Döllner,
Proceedings 9. Konferenz Kultur und Informatik - Multimediale Systeme 2011

Dieser Beitrag stellt die Ergebnisse des interdisziplinären Projektes Colonia3D - Visualisierung des Römischen Kölns vor. Die digitale 3D Rekonstruktion des antiken Köln ist das Ergebnis eines gemeinsamen Forschungsprojekts des Archäologischen Instituts der Universität zu Köln, der Köln International School of Design (KISD) der Fachhochschule Köln, des Hasso-Plattner Instituts an der Universität Potsdam und des Römisch Germanischen Museums (RGM) Köln. Der Beitrag präsentiert die wesentlichen Konzepte dieses interaktiven, auf Museen ausgerichteten 3D-Informationssystems, beschreibt verschiedene Präsentationsmodi und deren technische Umsetzung. Er diskutiert Vorgehensweisen und Interaktionskonzepte, die den Benutzer während der Erkundung und Bewegung im virtuellen 3D-Stadtmodell unterstützen. Weiter werden die Techniken für den Austausch, die Aufbereitung und die Optimierung komplexer 3D-Datensätze beschrieben sowie Potenziale für digitale Museen und Ausstellungen skizziert. Der vorgestellte Ansatz stellt insbesondere eine IT-Lösung für einen vereinfachten, räumlich-kontextintegrierten informellen Wissenszugang zu archäologischer Fachinformation dar.

BibTeX, Paper (PDF)

@inproceedings{TSD11,
  author = { Trapp, Matthias and Semmo, Amir and D{\"o}llner, J{\"u}rgen },
  title = { Colonia3D },
  booktitle = { Tagungsband der 9. Konferenz Kultur und Informatik - Multimediale Systeme },
  year = { 2011 },
  pages = { 201--212 },
  month = { 5 },
  publisher = { Werner H{\"u}lsbusch Verlag }
}

Ansätze zur kartographischen Gestaltung von 3D-Stadtmodellen

Amir Semmo, Matthias, Trapp, and Jürgen Döllner,
Proceedings 31. Wissenschaftlich-Technische Jahrestagung der DGPF 2011

Interaktive virtuelle 3D-Stadtmodelle haben sich zu einem bewährten Medium für die effektive und effiziente Kommunikation von Geoinformation entwickelt. Sie präsentieren eine spezialisierte Form geovirtueller Umgebungen und sind gekennzeichnet durch ein zugrunde liegendes 3D-Geländemodell, einer darin befindlichen 3D-Bebauung sowie des dazu komplementären Straßen-, Grünflächen- und Naturraumes. 3D-Stadtmodell-Systeme ermöglichen es dem Nutzer, sich im Modell interaktiv zu bewegen und sie stellen die Grundfunktionen für die Exploration, Analyse, Präsentation und das Editieren der raumbezogenen Information bereit. Besonders im Gebiet der kartenähnlichen und kartenverwandten 3D-Darstellungen stellen u.a. automatische Verfahren und Techniken zur Stilisierung und Abstraktion von Objekten eines 3D Stadtmodell ein Hauptproblem für die interaktive 3D-Bildsynthese dar. Hier spielt insbesondere die Abstraktion und Illustration potentiell wichtiger Information und somit die Reduzierung der kognitiven Belastung des Nutzers eine tragende Rolle. Diesbezüglich sind Verfahren und Techniken zur nicht-photorealistischen Bildsynthese ein bewährtes Mittel der Computergrafik, deren direkte Anwendung auf ein komplettes 3D-Stadtmodell jedoch häufig monotone sowie gestalterisch und kartographisch stark eingeschränkte Resultate liefert. Eine effiziente und kontextsensitive Kommunikation von 3D-Geoinformation bedarf jedoch der Kopplung von Objektsemantik und Abstraktionsverfahren. Diese Arbeit präsentiert ein Konzept und dessen Umsetzung, das die Auswahl und Parametrisierung von nicht-photorealistischen Darstellungstechniken auf Basis von Objektsemantiken erlaubt (Abbildung 1). Dies ermöglicht die Zuweisung unterschiedlicher automatischer Abstraktionstechniken zu Objekten und Objektgruppen. Der vorgestellte Ansatz ist echtzeitfähig und erlaubt eine interaktive Klassifikation von Objekten und Features zur Laufzeit, wodurch sich u.a. Szenarien zur interaktiven Exploration von thematisch-stilisierten Features bzw. feature-bezogenen Daten visualisieren lassen. Dieser Ansatz eröffnet Möglichkeiten für eine gezielte und systematische kartographische Gestaltung von 3D-Stadtmodellen sowie deren echtzeitfähige Implementierung durch entsprechende 3D-Visualisierungsdienste.

BibTeX, Paper (PDF)

@INPROCEEDINGS{STD11,
  author = {Semmo, Amir and Trapp, Matthias and J{\"u}rgen D{\"o}llner},
  title = {Ans{\"a}tze zur kartographischen Gestaltung von 3D-Stadtmodellen},
  booktitle = {31. Wissenschaftlich-Technische Jahrestagung der DGPF},
  year = {2011},
  pages = {473--482}
}

Anisotropic Kuwahara Filtering with Polynomial Weighting Functions

Jan Eric Kyprianidis, Amir Semmo, Henry Kang, and Jürgen Döllner,
NPAR Poster Session / Proceedings EG UK Theory and Practice of Computer Graphics (TP.CG) 2010

In this work we present new weighting functions for the anisotropic Kuwahara filter. The anisotropic Kuwahara filter is an edge-preserving filter that is especially useful for creating stylized abstractions from images or videos. It is based on a generalization of the Kuwahara filter that is adapted to the local shape of features. For the smoothing process, the anisotropic Kuwahara filter uses weighting functions that use convolution in their definition. For an efficient implementation, these weighting functions are therefore usually sampled into a texture map. By contrast, our new weighting functions do not require convolution and can be efficiently computed directly during the filtering in real-time. We show that our approach creates output of similar quality as the original anisotropic Kuwahara filter and present an evaluation scheme to compute the new weighting functions efficiently by using rotational symmetries.

BibTeX, Paper (PDF)

@inproceedings{KSKD10b,
  author = { Kyprianidis, Jan Eric and Semmo, Amir and Kang, Henry and D{\"o}llner, J{\"u}rgen },
  title = { Anisotropic Kuwahara Filtering with Polynomial Weighting Functions },
  booktitle = { Proc. EG UK Theory and Practice of Computer Graphics },
  year = { 2010 },
  pages = { 25--30 },
  month = { 9 }
}

@misc{KSKD10a,
  author = { Kyprianidis, Jan Eric and Semmo, Amir and Kang, Henry and D{\"o}llner, J{\"u}rgen },
  title = { Anisotropic Kuwahara Filtering with Polynomial Weighting Functions },
  booktitle = { NPAR Poster Session },
  month = { 6 },
  year = { 2010 }
}

Automated Image-Based Abstraction of Aerial Images

Amir Semmo, Jan Eric Kyprianidis, and Jürgen Döllner,
Proceedings of 13th AGILE International Conference on Geographic Information Science 2010

Aerial images represent a fundamental type of geodata with a broad range of applications in GIS and geovisualization. The perception and cognitive processing of aerial images by the human, however, still is faced with the specific limitations of photorealistic depictions such as low contrast areas, unsharp object borders as well as visual noise. In this paper we present a novel technique to automatically abstract aerial images that enhances visual clarity and generalizes the contents of aerial images to improve their perception and recognition. The technique applies non-photorealistic image processing by smoothing local image regions with low contrast and emphasizing edges in image regions with high contrast. To handle the abstraction of large images, we introduce an image tiling procedure that is optimized for post-processing images on GPUs and avoids visible artifacts across junctions. This is technically achieved by filtering additional connection tiles that overlap the main tiles of the input image. The technique also allows the generation of different levels of abstraction for aerial images by computing a mipmap pyramid, where each of the mipmap levels is filtered with adapted abstraction parameters. These mipmaps can then be used to perform level-of-detail rendering of abstracted aerial images. Finally, the paper contributes a study to aerial image abstraction by analyzing the results of the abstraction process on distinctive visible elements in common aerial image types. In particular, we have identified a high abstraction straction potential in landscape images and a higher benefit from edge enhancement in urban environments.

BibTeX, DOI, Paper (PDF)

@incollection{SKD10,
  author = { Semmo, Amir and Kyprianidis, Jan Eric and D{\"o}llner, J{\"u}rgen },
  title = { Automated Image-Based Abstraction of Aerial Images },
  booktitle = { Geospatial Thinking },
  publisher = { Springer },
  year = { 2010 },
  editor = { Painho, Marco and Santos, Maribel Yasmina and Pundt, Hardy },
  series = { Lecture Notes in Geoinformation and Cartography },
  pages = { 359--378 },
  month = { 5 },
  doi = { 10.1007/978-3-642-12326-9_19 }
}

ContextLua: Dynamic Behavioral Variations in Computer Games

Benjamin Hosain Wasty, Amir Semmo, Malte Appeltauer, Bastian Steinert, and Robert Hirschfeld,
Proceedings of 2nd International Workshop on Context-Oriented Programming 2010

Behavioral variations are central to modern computer games as they are making the gameplay a more interesting user experience. However, these variations significantly add to the implementation complexity. We discuss the domain of computer games with respect to dynamic behavioral variations and argue that context-oriented programming is of special interest for this domain. This motivates our extension to the dynamic scripting language Lua, which is frequently used in the development of computer games. Our newly provided programming constructs allow game developers to use layers for defining and activating variations of the basic gameplay.

BibTeX, Paper (ACM DL)

@inproceedings{WSASH10,
  author = { Hosain Wasty, Benjamin and Semmo, Amir and Appeltauer, Malte and Steinert, Bastian and Hirschfeld, Robert },
  title = { ContextLua: Dynamic Behavioral Variations in Computer Games },
  booktitle = { Proceedings of the 2nd International Workshop on Context-Oriented Programming },
  year = { 2010 },
  pages = { 5:1--5:6 },
  doi = { 10.1145/1930021.1930026 }
}

August 2017

Pictory: Combining Neural Style Transfer and Image Filtering

to be held at ACM SIGGRAPH (Appy Hour), Los Angeles, CA, USA

July 2017

Neural Style Transfer: A Paradigm Shift for Image-based Artistic Rendering?

to be held at Expressive 2017, Los Angeles, CA, USA

December 2016

Interactive Image Filtering with Multiple Levels-of-Control on Mobile Devices

ACM SIGGRAPH Asia Symposium on Mobile Graphics and Interactive Applications, Macao

December 2016

BeCasso: Artistic Image Processing and Editing on Mobile Devices

ACM SIGGRAPH Asia Symposium on Mobile Graphics and Interactive Applications (Demo Session), Macao

July 2016

Interactive Multi-scale Oil Paint Filtering on Mobile Devices

ACM SIGGRAPH (Poster Session), Anaheim, CA, USA

July 2016

BeCasso: Image Stylization by Interactive Oil Paint Filtering on Mobile Devices

ACM SIGGRAPH (Appy Hour), Anaheim, CA, USA

May 2016

Interactive Oil Paint Filtering On Mobile Devices

Expressive 2016 (Poster Session), Lisbon, Portugal

November 2015

Konzepte und Techniken für das kartographische Design von 3D geovirtuellen Umgebungen

SGK-Herbsttagung, Muttenz, Switzerland

August 2015

Cartography-Oriented Design of 3D Geospatial Information Visualization - Overview and Techniques

International Cartographic Conference 2015, Rio de Janeiro, Brazil

June 2015

Image Stylization by Oil Paint Filtering using Color Palettes

Expressive 2015, Istanbul, Turkey

November 2014

An Interaction Framework for Level-of-Abstraction Visualization of 3D Geovirtual Environments

ACM SIGSPATIAL MapInteract 2014, Dallas, TX, USA

August 2014

Image Filtering for Interactive Level-of-Abstraction Visualization of 3D Scenes

Expressive 2014, Vancouver, Canada

September 2013

Evaluating the Perceptual Impact of Rendering Techniques on Thematic Color Mappings in 3D Virtual Environments

International Workshop on Vision, Modeling and Visualization (VMV) 2013, Lugano, Switzerland

July 2013

Real-Time Rendering of Water Surfaces with Cartography-Oriented Design

Expressive 2013, Anaheim, CA, USA

June 2012

Interactive Visualization of Generalized Virtual 3D City Models using Level-of-Abstraction Transitions

Eurographics Conference on Visualization (EuroVis) 2012, Vienna, Austria

June 2012

Cartography-Oriented Visualization of Virtual 3D City Models based on Level-of-Abstraction Transitions

Hasso Plattner Institute / Research School, Potsdam, Germany

May 2012

Colonia3D

Kultur und Informatik Conference, Berlin, Germany

April 2011

Ansaetze zur kartographischen Gestaltung von 3D-Stadtmodellen

31. Wissenschaftlich-Technische Jahrestagung der DGPF, Mainz, Germany

May 2010

Automated Image-Based Abstraction of Aerial Images

AGILE International Conference on Geographic Information Science, Guimaraes, Portugal

2014/15 : Winter Term / Summer Term
  • Geovisualization

    seminar (MA), tutor
  • Introduction to Visualization

    lecture (MA), tutor
2013/14 : Winter Term / Summer Term
  • Geovisualization

    seminar (MA), tutor
  • Image & Video Processing

    seminar (BA), tutor
  • Video Analysis, Abstraction, and Summarization

    project (BA), tutor
2012/13 : Winter Term / Summer Term
  • Computergraphics II

    lecture (BA), tutor & co-lecturer
  • Graphics Programming with OpenGL and C++

    lecture/seminar (BA), tutor & lecturer
2011/12 : Winter Term / Summer Term
  • Real-Time Rendering Techniques

    seminar (MA), tutor
  • Computergraphics I

    lecture (BA), tutor
  • Computergraphics II

    lecture (BA), tutor
Program Committee
Expressive 2017, GeoVIS 2015 (ISPRS Geospatial Week)

Reviewing
ACM SIGGRAPH (2014), IEEE Transactions on Visualization and Computer Graphics (2015), Computers & Graphics (2016), Eurographics (2017), Eurographics Conference on Visualization / EuroVis (2014), IEEE Pacific Visualization (2013), IEEE MultiMedia (2016), International Journal of Geographical Information Science (2013), The Visual Computer (2012), Graphics Interface (2017), Vision, Modeling and Visualization (2016)

Memberships
ACM, ACM SIGGRAPH, IEEE

Awards & Honors
Best Demo @ SIGGRAPH Asia Symposium on Mobile Graphics and Interactive Applications, CGF Cover Contest 2016 (Runner-up), Best Paper Award @ Expressive - 2015, Cover Image Selection for Proceedings of EG UK TP.CG - 2013, Cover Image Selection for International Journal of Heritage in the Digital Era (vol. 1, no. 1) - 2012, Hasso Plattner Institute Best Diploma (M.Sc.) - 2011, Best Paper Award @ EuroMed Conference - 2010, Best technical research student paper @ EG UK TP.CG - 2010

Office

amir.semmo@hpi.de (mailto)

(+49) 0331 5509 3909

(+49) 0331 5509 172

Hasso-Plattner-Institut
Prof.-Dr.-Helmert-Strasse 2-3
14482 Potsdam, Germany

Room H-2.26

asemmo (GitHub, Bitbucket, ...)

Drop Me a Line

Send via Formspree.