Browsing by Subject "Depth perception"

Now showing 1 - 7 of 7

Open Access
Effects of coloured lighting on the perception of interior spaces
(SAGE, 2015-02-01) Odabaşioğlu, S.; Olguntürk, N.
Use of coloured lighting in interior spaces has become prevalent in recent years. Considerable importance is ascribed to coloured lighting in interior and lighting design. The effects of colour on the perception of interior spaces have been studied as surface colour; but here, the effects of three different types of chromatic light were investigated. The lighting differed in colour (red, green and white) and perceptions of interior space were assessed. 97 participants (59 women, 38 men; M age = 21.4 yr.) evaluated the experiment room on a questionnaire assessing eight evaluative factors: Pleasantness, Arousal, Aesthetics, Usefulness, Comfort, Spaciousness, Colour, and Lighting quality. Perceptions of the room differed by colour of lighting for some of the evaluative factors, but there was no sex difference in perceptions. Interior spaces may be perceived as equally pleasant under white, green and red lighting. Under white lighting a space is perceived as more useful, spacious, clear, and luminous. Green lighting would make the same effect. Green and white lighting were perceived equally comfortable in an interior space. Chromatic coloured lighting was perceived to be more aesthetic than white lighting. The results support previous findings for some evaluative factors, but differed for others.
Open Access
A framework for applying the principles of depth perception to information visualization
(Association for Computing Machinery, 2013) Zeynep, C. Y.; Bulbul, A.; Capin, T.
During the visualization of 3D content, using the depth cues selectively to support the design goals and enabling a user to perceive the spatial relationships between the objects are important concerns. In this novel solution, we automate this process by proposing a framework that determines important depth cues for the input scene and the rendering methods to provide these cues. While determining the importance of the cues, we consider the user's tasks and the scene's spatial layout. The importance of each depth cue is calculated using a fuzzy logic-based decision system. Then, suitable rendering methods that provide the important cues are selected by performing a cost-profit analysis on the rendering costs of the methods and their contribution to depth perception. Possible cue conflicts are considered and handled in the system. We also provide formal experimental studies designed for several visualization tasks. A statistical analysis of the experiments verifies the success of our framework. © 2013 ACM.
Open Access
A framework for enhancing depth perception in computer graphics
(ACM, 2010-07) Çipiloğlu, Zeynep; Bülbül, Abdullah; Çapin, Tolga
This paper introduces a solution for enhancing depth perception in a given 3D computer-generated scene. For this purpose, we propose a framework that decides on the suitable depth cues for a given scene and the rendering methods which provide these cues. First, the system calculates the importance of each depth cue using a fuzzy logic based algorithm which considers the target tasks in the application and the spatial layout of the scene. Then, a knapsack model is constructed to keep the balance between the rendering costs of the graphical methods that provide these cues and their contibution to depth perception. This cost-profit analysis step selects the proper rendering methods. In this work, we also present several objective and subjective experiments which show that our automated depth enhancement system is statistically (p < 0.05) better than the other method selection techniques that are tested. © 2010 ACM.
Open Access
A fuzzy logic based approach for enchanging depth perception in computer graphics
(2010) Çipiloğlu, Zeynep
Rapid progress in 3D rendering and display technologies brings the problem of better visualization of 3D content. Providing correct depth information and enabling the user to perceive the spatial relationship between the objects is one of the main concerns during the visualization of 3D content. In this thesis, we introduce a solution that can either be used for automatically enhancing the depth perception of a given scene, or as a component that suggests suitable rendering methods to application developers. In this novel solution, we propose a framework that decides on the suitable depth cues for a given 3D scene and the rendering methods which provide these cues. First, the system calculates the importance of each depth cue using a fuzzy logic based algorithm which considers the user's tasks in the application and the spatial layout of the scene. Then, a knapsack model is constructed to keep the balance between the rendering costs of the graphical methods that provide these cues and their contribution to depth perception. This cost-pro t analysis step selects the proper rendering methods for the given scene. In this work, we also present several objective and subjective experiments which show that our automated depth perception enhancement system is statistically (p < 0.05 ) better than the other method selection techniques that are tested.
Open Access
Joint estimation and optimum encoding of depth field for 3-D object-based video coding
(IEEE, 1996-09) Alatan, A. Aydın; Onural, Levent
3-D motion models can be used to remove temporal redundancy between image frames. For efficient encoding using 3-D motion information, apart from the 3-D motion parameters, a dense depth field must also be encoded to achieve 2-D motion compensation on the image plane. Inspiring from Rate-Distortion Theory, a novel method is proposed to optimally encode the dense depth fields of the moving objects in the scene. Using two intensity frames and 3-D motion parameters as inputs, an encoded depth field can be obtained by jointly minimizing a distortion criteria and a bit-rate measure. Since the method gives directly an encoded field as an output, it does not require an estimate of the field to be encoded. By efficiently encoding the depth field during the experiments, it is shown that the 3-D motion models can be used in object-based video compression algorithms.
Open Access
Paper and pen: A 3D sketching system
(Springer, 2013-10) Yıldız, Cansın; Çapın, Tolga
This paper proposes a method that resembles a natural pen and paper interface to create curve based 3D sketches. The system is particularly useful for representing initial 3D design ideas without much effort. Users interact with the system by the help of a pressure sensitive pen tablet. The input strokes of the users are projected onto a drawing plane, which serves as a paper that they can place anywhere in the 3D scene. The resulting 3D sketch is visualized emphasizing depth perception. Our evaluation involving several naive users suggest that the system is suitable for a broad range of users to easily express their ideas in 3D. We further analyze the system with the help of an architect to demonstrate the expressive capabilities. © 2013 Springer-Verlag London.
Open Access
Perceptually-driven computer graphics and visualization
(2016-10) Yıldız, Zeynep Çipiloğlu
Despite the rapid advances in computer graphics technology, enhancing the visual quality and lowering the rendering cost is still the essential goal for computer graphics researchers; since improvements in computational power raise the users' expectations too. Especially in interactive 3D games and cinema industry, very realistic graphical contents are desired in real-time. In the meantime, due to the increasing popularity of social networking systems and data sharing, there is a huge amount of data to be visualized effectively. When used carefully, 3D introduces a new data channel for information visualization applications. For that reason, improving the visual quality of 3D computer-generated scenes is still of great interest in the computer graphics and visualization community. In the last decade, utilization of visual perception findings in computer graphics has started to get popular since visual quality is actually judged by the human perception and there is no need to spend additional cost for the physical realism of the details that cannot be perceived by the observer. There is still room for employing the perceptual principles in computer graphics. We contribute to the perceptual computer graphics research in two main aspects: First we propose several perceptual error metrics for evaluating the visual quality of static or animated 3D meshes. Second, we develop a system for ameliorating the perceived depth quality and comprehensibility in 3D visualization applications. A measure for assessing the quality of a 3D mesh is necessary in order to determine whether an operation on the mesh, such as watermarking or compression, affects the perceived quality. The studies on this field are limited when compared to the studies for 2D. A bottom-up approach incorporating both the spatial and temporal components of the low-level human visual system processes is suggested to develop a general-purpose quality metric designed to measure the local distortion visibility on dynamic triangle meshes. In addition, application of crowdsourcing and machine learning methods to implement a novel data-driven error metric for 3D models is also demonstrated. During the visualization of 3D content, using the depth cues selectively to support the design goals and enabling a user to perceive the spatial relationships between the objects are important concerns. In this regard, a framework for selecting proper depth cues and rendering methods providing these cues for the given scene and visualization task is put forward. This framework benefits from fuzzy logic for determining the importance of depth cues and knapsack method for modeling the cost-profit tradeoff between the rendering costs of the methods and their contribution to depth perception. All the proposed methods in this study are validated through formal user experiments and we obtain encouraging results for further research. These results are made publicly available for the benefit of graphics community. In conclusion, we try to make the gap between visual perception and computer graphics fields narrower with the suggested methods in this work.