TY  - JOUR
A1  - Semmo, Amir
A1  - Döllner, Jürgen Roland Friedrich
T1  - Interactive image filtering for level-of-abstraction texturing of virtual 3D scenes
JF  - Computers & graphics : CAG ; an international journal of applications in computer graphics
N2  - Texture mapping is a key technology in computer graphics. For the visual design of 3D scenes, in particular, effective texturing depends significantly on how important contents are expressed, e.g., by preserving global salient structures, and how their depiction is cognitively processed by the user in an application context. Edge-preserving image filtering is one key approach to address these concerns. Much research has focused on applying image filters in a post-process stage to generate artistically stylized depictions. However, these approaches generally do not preserve depth cues, which are important for the perception of 3D visualization (e.g., texture gradient). To this end, filtering is required that processes texture data coherently with respect to linear perspective and spatial relationships. In this work, we present an approach for texturing 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, using (3) direct interaction interfaces to parameterize the visualization according to spatial, semantic, and thematic data. We demonstrate the potentials of our method by several applications using touch or natural language inputs to serve the different interests of users in specific information, including illustrative visualization, focus+context visualization, geometric detail removal, and semantic depth of field. The approach supports frame-to-frame coherence, order-independent transparency, multitexturing, and content-based filtering. In addition, it seamlessly integrates into real-time rendering pipelines and is extensible for custom interaction techniques. (C) 2015 Elsevier Ltd. All rights reserved.
KW  - Image filtering
KW  - Level of abstraction
KW  - Texturing
KW  - Virtual 3D scenes
KW  - Visualization
KW  - Interaction
Y1  - 2015
U6  - https://doi.org/10.1016/j.cag.2015.02.001
SN  - 0097-8493
SN  - 1873-7684
VL  - 52
SP  - 181
EP  - 198
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Semmo, Amir
A1  - Trapp, Matthias
A1  - Jobst, Markus
A1  - Döllner, Jürgen Roland Friedrich
T1  - Cartography-Oriented Design of 3D Geospatial Information Visualization - Overview and Techniques
JF  - The cartographic journal
N2  - In economy, society and personal life map-based interactive geospatial visualization becomes a natural element of a growing number of applications and systems. The visualization of 3D geospatial information, however, raises the question how to represent the information in an effective way. Considerable research has been done in technology-driven directions in the fields of cartography and computer graphics (e.g., design principles, visualization techniques). Here, non-photorealistic rendering (NPR) represents a promising visualization category - situated between both fields - that offers a large number of degrees for the cartography-oriented visual design of complex 2D and 3D geospatial information for a given application context. Still today, however, specifications and techniques for mapping cartographic design principles to the state-of-the-art rendering pipeline of 3D computer graphics remain to be explored. This paper revisits cartographic design principles for 3D geospatial visualization and introduces an extended 3D semiotic model that complies with the general, interactive visualization pipeline. Based on this model, we propose NPR techniques to interactively synthesize cartographic renditions of basic feature types, such as terrain, water, and buildings. In particular, it includes a novel iconification concept to seamlessly interpolate between photorealistic and cartographic representations of 3D landmarks. Our work concludes with a discussion of open challenges in this field of research, including topics, such as user interaction and evaluation.
KW  - 3D information visualization
KW  - 3D semiotic model
KW  - cartographic design
KW  - user interaction
KW  - real-time rendering
Y1  - 2015
U6  - https://doi.org/10.1080/00087041.2015.1119462
SN  - 0008-7041
SN  - 1743-2774
VL  - 52
IS  - 2
SP  - 95
EP  - 106
PB  - Routledge, Taylor & Francis Group
CY  - Leeds
ER  -