nils-herrmann/clean_scirepeval huggingface dataset:
Coding and intermediate view synthesis of multiview video plus depth

For advanced 3D Video (3DV) applications, efficient data representations are investigated, which only transmit a subset of the views that are required for 3D visualization. From this subset, all intermediate views are synthesized from sample-dense color and depth data. In this paper, the method for reliability-based view synthesis from compressed multi-view + depth data (MVD) is investigated and corresponding results are shown. The initial problem in such 3DV systems is the interdependency between view capturing, coding and view synthesis. For evaluating each component separately, we first generate results from the coding stage only, where color and depth coding is carried out separately. In the next step, we add the view synthesis stage with reliability-based view synthesis and show, how the separate coding results influence the view synthesis quality and what type of artifacts are produced. Efficient bit rate distribution between color and depth is investigated by objective as well as subjective evaluations. Furthermore, quality characteristics across the viewing range for different bit rate distributions are analyzed. Finally, the robustness of the reliability-based view synthesis to coding artifacts is presented.
Efficient representation and interactive streaming of high-resolution panoramic views

A new system for interactive streaming of high-resolution 360/spl deg/ panoramic views over the Internet is presented. The scene is represented very efficiently using MPEG-4 BIFS and displayed at the client using the HHI 3-D MPEG-4 player. The user can navigate interactively through the scene. The navigation decisions are evaluated to trigger the streaming of the data needed to build the visible screen view and to ensure a fluent visualization of the scene. The system layout is designed to support other, more complex photo realistic 3-D environments later on and, thus, will enable the provision of a variety of new, interactive services over the Internet.
Interactive 3-D Video Representation and Coding Technologies

Interactivity in the sense of being able to explore and navigate audio-visual scenes by freely choosing viewpoint and viewing direction, is an important key feature of new and emerging audio-visual media. This paper gives an overview of suitable technology for such applications, with a focus on international standards, which are beneficial for consumers, service providers, and manufacturers. We first give a general classification and overview of interactive scene representation formats as commonly used in computer graphics literature. Then, we describe popular standard formats for interactive three-dimensional (3-D) scene representation and creation of virtual environments, the virtual reality modeling language (VRML), and the MPEG-4 BInary Format for Scenes (BIFS) with some examples. Recent extensions to MPEG-4 BIFS, the Animation Framework eXtension (AFX), providing advanced computer graphics tools, are explained and illustrated. New technologies mainly targeted at reconstruction, modeling, and representation of dynamic real world scenes are further studied. The user shall be able to navigate photorealistic scenes within certain restrictions, which can be roughly defined as 3-D video. Omnidirectional video is an extension of the planar two-dimensional (2-D) image plane to a spherical or cylindrical image plane. Any 2-D view in any direction can be rendered from this overall recording to give the user the impression of looking around. In interactive stereo two views, one for each eye, are synthesized to provide the user with an adequate depth cue of the observed scene. Head motion parallax viewing can be supported in a certain operating range if sufficient depth or disparity data are delivered with the video data. In free viewpoint video, a dynamic scene is captured by a number of cameras. The input data are transformed into a special data representation that enables interactive navigation through the dynamic scene environment.
Development of a new MPEG standard for advanced 3D video applications

An overview of available 3D video formats and standards is given. It is explained why none of these - although each useful in some particular sense, for some particular application - satisfies all requirements of all 3D video applications. Advanced formats currently under investigation, which have the potential to serve as generic, flexible and efficient future 3D video standard are explained. Then an activity of MPEG for development of such a new standard is described and an outlook to future developments is given.
Improved H.264/AVC coding using texture analysis and synthesis

We assume that the textures in a video scene is classified into two categories: textures with unimportant subjective details and the remainder. We utilize this assumption for improved video coding using a texture analyzer and a texture synthesizer. The texture analyzer identifies the texture regions with unimportant subjective details and generates coarse masks as well as side information for the texture synthesizer at the decoder side. The texture synthesizer replaces the identified textures by inserting synthetic textures for the identified regions. The texture analyzer is based on MPEG-7 descriptors. Our approach is integrated into an H.264/AVC codec. Bit-rate savings up to 19.4% are shown for a semi-automatic texture analyzer given similar subjective quality as the H.264/AVC codec without the presented approach.
3-D reconstruction of a dynamic environment with a fully calibrated background for traffic scenes

Vision-based traffic surveillance systems are more and more employed for traffic monitoring, collection of statistical data and traffic control. We present an extension of such a system that additionally uses the captured image content for 3-D scene modeling and reconstruction. A basic goal of surveillance systems is to get a good coverage of the observed area with as few cameras as possible to keep the costs low. Therefore, the 3-D reconstruction has to be done from only a few original views with limited overlap and different lighting conditions. To cope with these specific restrictions we developed a model-based 3-D reconstruction scheme that exploits a priori knowledge about the scene. The system is fully calibrated offline by estimating camera parameters from measured 3-D-2-D correspondences. Then the scene is divided into static parts, which are modeled offline and dynamic parts, which are processed online. Therefore, we segment all views into moving objects and static background. The background is modeled as multitexture planes using the original camera textures. Moving objects are segmented and tracked in each view. All segmented views of a moving object are combined to a 3-D object, which is positioned and tracked in 3-D. Here we use predefined geometric primitives and map the original textures onto them. Finally the static and dynamic elements are combined to create the reconstructed 3-D scene, where the user can freely navigate, i.e., choose an arbitrary viewpoint and direction. Additionally, the system allows analyzing the 3-D properties of the scene and the moving objects.
Mixed resolution coding of stereoscopic video for Mobile devices

This paper presents results for full and mixed resolution stereo video coding including subjective and objective evaluation for 3DTV on Mobile devices. For this, objective as well as subjective tests have been carried out with different sequences at different image sizes and evaluated on two different stereoscopic displays. The subjective tests showed, that for uncoded sequences full resolution was rated better, however for coded sequences at low bit rates mixed resolution was rated better. An unsharp masking algorithm for up-sampling the lower resolution view only partially improved the overall quality because coding artifacts were strengthened as well. Objective tests showed that the optimum bit rate distribution for mixed resolution stereo video coding is 30% to 35% of the total bit rate for the lower resolution view (half horizontal and half vertical). Finally, tests showed that mixed resolution stereo video decoding with up-sampling is less complex than decoding full resolution stereo video which is important for implementation on mobile devices.
A Flexible 3D TV System for Different Multi-Baseline Geometries

Interoperability, scalability and adaptability are important features for a successful introduction of future 3D TV services. Hence, new concepts must be able to adapt the multi-view geometry of the capturing system to the geometry of the 3D reproduction systems. An approach is discussed, which considers these adaptation issues based on the concept of an Ntimesvideo-plus-depth data representation. The core algorithms for depth map creation on the analysis side and depth image based rendering on the reproduction side are presented
Evaluation of backward mapping DIBR for FVV applications

In this paper, we explore the challenges posed by wide baseline camera configurations for depth-image-based rendering, which should provide greater freedom for choosing the virtual viewpoint in a Free Viewpoint Video context, compared with the usual camera configurations intended for use in 3DTV settings. We implement a backward mapping approach with a custom filtering scheme based on median filters. Whilst the results back our initial assumption that this camera configuration provides good mobility, we show that the usual encoding for depth information referred to a global reference system is wrong and reference systems local to each camera should be used instead.
MADmax: A 1080p stereo-to-multiview rendering ASIC in 65 nm CMOS based on image domain warping

In this paper, a video rendering ASIC for multiview automultiscopic displays using an image domain warping approach is presented. The video rendering core is able to synthesize up to nine interleaved views from full-HD (1080p) stereoscopic 3D input footage. The design employs elliptical weighted average (EWA) splatting to perform the image resampling. We use the mathematical properties of the Gaussian filters of EWA splatting to analytically integrate display anti-aliasing into the resampling step. The use of realistic assumptions on the image transformation enable a hardware architecture that operates on a video stream in scan-line fashion and that does not require an off-chip memory. The ASIC, fabricated in a 65nm CMOS technology, runs at 260MHz and is able to deliver 28.7 interleaved full-HD (1080p) frames per second with eight views enabled. It has a core power dissipation of 550mW and its complexity is 6.8 MGE, including 4.36 MBit SRAM macros.
Non-linear warping and warp coding for content-adaptive prediction in advanced video coding applications

This paper presents a new concept for scalable video coding, which is content adaptive and art-directable. Video retargeting is applied to scale video between different resolutions and aspect ratios without introducing inacceptable distortions or cutting off content. The non-linear warping operations are integrated into a spatial scalability framework, which includes two new building blocks, i.e. non-linear warping prediction and warp coding. Efficient algorithms for both processes are presented, tested and optimized. The presented results indicate that our non-linear scaling and warp coding algorithms provide efficient performance compared to standard linear scaling methods. Further, our advanced scaling algorithms, i.e. EWA splatting in combination with backward mapping, may be very useful for linear scaling as well.
Disparity-Aware Stereo 3D Production Tools

Stereoscopic 3D (S3D) has reached wide levels of adoption in consumer and professional markets. However, production of high quality S3D content is still a difficult and expensive art. Various S3D production tools and systems have been released recently to assist high quality content creation. This paper presents a number of such algorithms, tools and systems developed at Disney Research Zurich, which all make use of disparity-aware processing.
2D to 3D conversion of sports content using panoramas

Given video from a single camera, conversion to two-view stereoscopic 3D is a challenging problem. We present a system to automatically create high quality stereoscopic video from monoscopic footage of field-based sports by exploiting context-specific priors, such as the ground plane, player size and known background. Our main contribution is a novel technique that constructs per-shot panoramas to ensure temporally consistent stereoscopic depth in video reconstructions. Players are rendered as billboards at correct depths on the ground plane. Our method uses additional sports priors to disambiguate segmentation artifacts and produce synthesized 3D shots that are in most cases, indistinguishable from stereoscopic ground truth footage.
Automated Aesthetic Analysis of Photographic Images

We present a perceptually calibrated system for automatic aesthetic evaluation of photographic images. Our work builds upon the concepts of no-reference image quality assessment, with the main difference being our focus on rating image aesthetic attributes rather than detecting image distortions. In contrast to the recent attempts on the highly subjective aesthetic judgment problems such as binary aesthetic classification and the prediction of an image's overall aesthetics rating, our method aims on providing a reliable objective basis of comparison between aesthetic properties of different photographs. To that end our system computes perceptually calibrated ratings for a set of fundamental and meaningful aesthetic attributes, that together form an “aesthetic signature” of an image. We show that aesthetic signatures can still be used to improve upon the current state-of-the-art in automatic aesthetic judgment, but also enable interesting new photo editing applications such as automated aesthetic analysis, HDR tone mapping evaluation, and providing aesthetic feedback during multi-scale contrast manipulation.
Image quality vs rate optimized coding of warps for view synthesis in 3D video applications

In this paper, a method for efficient warp coding is presented. Coded warps are transmitted together with stereo or multi-view video to enable additional functionalities at the receiver-side through image-domain-warping, e.g. depth adaption for stereo displays or support of multi-view autostereoscopic displays. Warp coding is performed by partitioning warps using a resolution pyramid and predictively exploiting intra and inter partition dependencies. View synthesis is employed within the coding loop to control the overall coding process, i.e. to evaluate the contribution of coded partitions to the synthesis quality. It is shown that coded warps represent a practically negligible portion of about 3.6% of the overall (video+warp) bit rate. Furthermore, it is shown that a transmission of warps leads to a reduction of synthesis time up to a factor of 8 in comparison to a fully automatic receiver-side view synthesis which uses only decoded video as input.
An Advanced 3DTV Concept Providing Interoperability and Scalability for a Wide Range of Multi-Baseline Geometries

The paper discusses an advanced approach for 3DTV services that is based on the concept of an N× video-plus-depth data representation. It particularly considers aspects of interoperability, scalability, and adaptability for the case that different multi-baseline geometries are used for multi-view capturing and 3D reproduction. In addition, it presents a method for the creation of depth maps and an algorithm for depth-image-based rendering related to the system approach.
3D Video and Free Viewpoint Video - Technologies, Applications and MPEG Standards

An overview of 3D and free viewpoint video is given in this paper with special focus on related standardization activities in MPEG. Free viewpoint video allows the user to freely navigate within real world visual scenes, as known from virtual worlds in computer graphics. Examples are shown, highlighting standards conform realization using MPEG-4. Then the principles of 3D video are introduced providing the user with a 3D depth impression of the observed scene. Example systems are described again focusing on their realization based on MPEG-4. Finally multi-view video coding is described as a key component for 3D and free viewpoint video systems. The conclusion is that the necessary technology including standard media formats for 3D and free viewpoint is available or will be available in the near future, and that there is a clear demand from industry and user side for such applications. 3D TV at home and free viewpoint video on DVD will be available soon, and will create huge new markets
Scene Representation Technologies for 3DTV—A Survey

3-D scene representation is utilized during scene extraction, modeling, transmission and display stages of a 3DTV framework. To this end, different representation technologies are proposed to fulfill the requirements of 3DTV paradigm. Dense point-based methods are appropriate for free-view 3DTV applications, since they can generate novel views easily. As surface representations, polygonal meshes are quite popular due to their generality and current hardware support. Unfortunately, there is no inherent smoothness in their description and the resulting renderings may contain unrealistic artifacts. NURBS surfaces have embedded smoothness and efficient tools for editing and animation, but they are more suitable for synthetic content. Smooth subdivision surfaces, which offer a good compromise between polygonal meshes and NURBS surfaces, require sophisticated geometry modeling tools and are usually difficult to obtain. One recent trend in surface representation is point-based modeling which can meet most of the requirements of 3DTV, however the relevant state-of-the-art is not yet mature enough. On the other hand, volumetric representations encapsulate neighborhood information that is useful for the reconstruction of surfaces with their parallel implementations for multiview stereo algorithms. Apart from the representation of 3-D structure by different primitives, texturing of scenes is also essential for a realistic scene rendering. Image-based rendering techniques directly render novel views of a scene from the acquired images, since they do not require any explicit geometry or texture representation. 3-D human face and body modeling facilitate the realistic animation and rendering of human figures that is quite crucial for 3DTV that might demand real-time animation of human bodies. Physically based modeling and animation techniques produce impressive results, thus have potential for use in a 3DTV framework for modeling and animating dynamic scenes. As a concluding remark, it can be argued that 3-D scene and texture representation techniques are mature enough to serve and fulfill the requirements of 3-D extraction, transmission and display sides in a 3DTV scenario.
From 2D- to Stereo- to Multi-view Video

This paper presents a new approach for generation of multi-view video from monocular video. Such multi-view video is used for instance with multi-user 3D displays or auto-stereoscopic displays with head-tracking to create a depth impression of the observed scenery. The intention of this work is not a real-time conversion of existing video material with a deduction in stereo perception, but rather a more realistic off-line conversion with high accuracy. Our approach is based on structure from motion techniques and uses image-based rendering to generate the desired multiple views for each point in time. The algorithm is tested on several TV broadcast videos, as well as on sequences captured with a single handheld camera. Finally, some simulation results will show the remarkable performance of this approach.
REVERIE: Natural human interaction in virtual immersive environments

REVERIE (REal and Virtual Engagement in Realistic Immersive Environments ) targets novel research to address the demanding challenges involved with developing state-of-the-art technologies for online human interaction. The REVERIE framework enables users to meet, socialise and share experiences online by integrating cutting-edge technologies for 3D data acquisition and processing, networking, autonomy and real-time rendering. In this paper, we describe the innovative research that is showcased through the REVERIE integrated framework through richly defined use-cases which demonstrate the validity and potential for natural interaction in a virtual immersive and safe environment. Previews of the REVERIE demo and its key research components can be viewed at www.youtube.com/user/REVERIEFP7.
Long-term global motion estimation and its application for sprite coding, content description, and segmentation

We present a new technique for long-term global motion estimation of image objects. The estimated motion parameters describe the continuous and time-consistent motion over the whole sequence relatively to a fixed reference coordinate system. The proposed method is suitable for the estimation of affine motion parameters as well as for higher order motion models like the parabolic model-combining the advantages of feature matching and optical flow techniques. A hierarchical strategy is applied for the estimation, first translation, affine motion, and finally higher order motion parameters, which is robust and computationally efficient. A closed-loop prediction scheme is applied to avoid the problem of error accumulation in long-term motion estimation. The presented results indicate that the proposed technique is a very accurate and robust approach for long-term global motion estimation, which can be used for applications such as MPEG-4 sprite coding or MPEG-7 motion description. We also show that the efficiency of global motion estimation can be significantly increased if a higher order motion model is applied, and we present a new sprite coding scheme for on-line applications. We further demonstrate that the proposed estimator serves as a powerful tool for segmentation of video sequences.
Predictive compression of dynamic 3D meshes

An efficient algorithm for compression of dynamic time-consistent 3D meshes is presented. Such a sequence of meshes contains a large degree of temporal statistical dependencies that can be exploited for compression using DPCM. The vertex positions are predicted at the encoder from a previously decoded mesh. The difference vectors are further clustered in an octree approach. Only a representative for a cluster of difference vectors is further processed providing a significant reduction of data rate. The representatives are scaled and quantized and finally entropy coded using CABAC, the arithmetic coding technique used in H.264/MPEG4-AVC. The mesh is then reconstructed at the encoder for prediction of the next mesh. In our experiments we compare the efficiency of the proposed algorithm in terms of bit-rate and quality compared to static mesh coding and interpolator compression indicating a significant improvement in compression efficiency.