nils-herrmann/clean_scirepeval huggingface dataset:
Depth Map Compression Using Color-Driven Isotropic Segmentation and Regularised Reconstruction

"View-plus-depth" is a popular 3D image representation format, in which the color 2D image is augmented with a gray-scale image representing the scene depth map aligned with the color pixels. In this paper, we propose a novel depth map compression method aimed at finding an optimal spatial depth scale and down-sampling (sparsifying) the depth image over it. The down-sampled depth image is then compressed by a combination of a new arithmetic and a predictive coder. Our approach is motivated by the current achievements in multi-sensor 3D scene sensing where low-resolution depth map captured by time-of-flight sensors is successfully up-sampled and aligned with high resolution RGB images. In our approach, color image segmentation in terms of super-pixels is used for finding the optimal depth scale and corresponding down-sampling. In contrast to other segmentation methods, it results in an isotropic and balanced low-resolution depth image, which is easily compressible. A bilateral regularizer is used for reconstructing the original-size depth map out of the low-resolution one and for splitting and predictive coding of segments with high reconstruction error. The scheme compares favorably with other methods for depth map compression.
Stereo video broadcast over DVB-H

This paper presents modelling and analysis of a mobile 3DTV broadcast system for handheld devices. The underlying technology behind our system is the DVB-H specification which brings ordinary TV broadcast services to battery-powered handheld receivers. In our system, we simulated the broadcast of stereo video content over DVB-H to mobile handheld devices with autostereoscopic displays. In this way, mobile users can watch 3D content without need for eyeglasses or any special equipment.
Feature extraction for heartbeat classification using independent component analysis and matching pursuits

We present a method based on the matching pursuits algorithm for the extraction of time-frequency features that can be used for classification of various abnormal heartbeats. Further, we investigate the usefulness of independent component analysis for extracting additional spatial features from multichannel electrocardiographic recordings. The performance of these two different sets of features is assessed using the 48 recordings of the MIT-BIH arrhythmia database.
Self-contained slices in H.264 for partial video decoding targeting 3D light-field displays

Some video applications work with parallel bitstreams however only parts of them are required. Decoding the streams entirely might be prohibitive due to high number of video streams and / or high resolution or bitrate of the streams. In such cases, a random access also referred as to partial decoding has to be supported. It can be achieved with a conforming decoder, if the video is separated into individual slices, and the unnecessary slices are dropped from the bit stream. Such a feature is essential in 3D lightfield displays in which partial decoding of bitstreams helps providing less complex and thus real-time decoding and processing. This paper studies the problem of creating self-contained (i.e., independently decodable) slices in an H.264 stream. The requirements that need to be fulfilled in order to build selfcontained slices are described, and an encoder-side solution is proposed. The advantages of self-contained slices are examined in the context of a light-field rendering application that relies on partial decoding.
Improving the transform domain ECG denoising performance by applying interbeat and intra-beat decorrelating transforms

A method for suppression of electromyogram (EMG) interference in electrocardiogram (EGG) recordings is presented, It combines inter-beats and intra-beats decorrelation techniques with transform domain Wiener filtering. The interbeats relations are kept by a short window DCT over multichannel data representing the successive beats, and the Wiener filtering is performed in translation-invariant wavelet domain. The method results in improved signal-to-noise ratio of the processed signals and reduced ripple artifacts around the signal transients, thus preserving the true waveform in diagnostically important signal segments. The algorithm's structure allows an on-line parallel processing and can be built in the ECG registration systems.
CPU-efficient free view synthesis based on depth layering

In this paper, a new approach for depth-image based rendering (DIBR) based on depth layering is proposed. The approach effectively avoids the non-uniform to uniform resampling stage, which is otherwise inherent for classical DIBR. In contrast, the new approach employs depth layering, which approximates the scene geometry by a multi-planar surface, given the depth is defined within a closed range. Such an approximation facilitates a fast reverse coordinate mapping from virtual to reference view where straightforward resampling on a uniform grid is performed. The proposed rendering approach ensures an automatic z-ordering and disocclusion detection, while being very efficient even for CPU-based implementations. It is also applicable for reference and virtual views with different resolutions and as such can serve depth upsampling, view panning and zooming applications. The experimental results demonstrate its real-time capability, while the quality is comparable with other view synthesis approaches but for lower computational cost.
Circular trajectory correspondences for iterative closest point registration

Iterative closest point (ICP) is a popular algorithm for finding rigid transformations between 3D point clouds. It aims to find the rotation and translation differences between the point clouds. A key component in the algorithm is finding correspondences between the two data sets, which are then used to determine the differences. A method for finding these pairings is described, utilizing the circular trajectory of points when the cloud is being rotated. The proposed method reveals more information per iteration cycle than techniques previously used for 3D data. The method enables the use of an efficient implementation by using a simple data structure, which has the same computational complexity to build and to access as the k-d tree commonly used with nearest neighbor correspondence searches. The experimental results show that the convergence rate is superior to the original ICP based on point-to-point minimization and compares favorably to more refined and complex approaches, e.g. normal shooting with point to plane minimization. This together with the efficient implementation strategy and low amount of computation per iteration makes the circular trajectory correspondences (CTC) a valid choice for registration tasks, especially in applications where processing power is limited.
Speed-optimized free-viewpoint rendering based on depth layering

In this paper free-viewpoint rendering is addressed and a new fast approach for virtual views synthesis from view-plus-depth 3D representation is proposed. Depth layering in disparity domain is employed in order to optimally approximate the scene geometry by a set of constant depth layers. This approximation facilitates the use of connectivity information for segment-based forward warping of the reference layer map, producing a complete virtual view layer map containing no cracks or holes. The warped layer map is used to guide the disocclusions inpainting process of the synthesized texture map. For this purpose, a speed-optimized patch-based inpainting approach is proposed. In contrast to the existing methods, patch similarity function is based on local binary patterns descriptors. Such binary representation allows for efficient processing and comparison of patches, as well as compact storage and reuse of previously calculated binary descriptors. The experimental results demonstrate realtime capability of the proposed method even for CPU-based implementation, while the quality is comparable with other view synthesis approaches.
Source and channel coding recipes for mobile 3D television

The paper overviews the transmission chain of 3D television for mobile services with special emphasis on stereoscopic video transmission. Specifically, methods for source and channel coding are overviewed for their suitability for such applications. They are analyzed in terms of performance and complexity as well as in terms of user acceptance and satisfaction. Furthermore, viewing conditions involving mobile auto-stereoscopic displays are analyzed emphasizing the limitations of those displays, such as accommodation-convergence rivalry and inter-view cross-talk along with corrective measures such as anti-aliasing filtering and comfort zone maintenance. Extensive subjective tests studying the importance of visual 3D cues on portable displays and visibility of artifacts are presented. Thus, the visualization conditions are put against the processing methods in order to prescribe practical optimal selection of source-channel coding methods.
Three-Dimensional Media for Mobile Devices

This paper aims at providing an overview of the core technologies enabling the delivery of 3-D Media to next-generation mobile devices. To succeed in the design of the corresponding system, a profound knowledge about the human visual system and the visual cues that form the perception of depth, combined with understanding of the user requirements for designing user experience for mobile 3-D media, are required. These aspects are addressed first and related with the critical parts of the generic system within a novel user-centered research framework. Next-generation mobile devices are characterized through their portable 3-D displays, as those are considered critical for enabling a genuine 3-D experience on mobiles. Quality of 3-D content is emphasized as the most important factor for the adoption of the new technology. Quality is characterized through the most typical, 3-D-specific visual artifacts on portable 3-D displays and through subjective tests addressing the acceptance and satisfaction of different 3-D video representation, coding, and transmission methods. An emphasis is put on 3-D video broadcast over digital video broadcasting-handheld (DVB-H) in order to illustrate the importance of the joint source-channel optimization of 3-D video for its efficient compression and robust transmission over error-prone channels. The comparative results obtained identify the best coding and transmission approaches and enlighten the interaction between video quality and depth perception along with the influence of the context of media use. Finally, the paper speculates on the role and place of 3-D multimedia mobile devices in the future internet continuum involving the users in cocreation and refining of rich 3-D media content.
MOBILE3DTV: Content Delivery Optimization over DVB-H System

Mobile TV has recently received a lot of attention worldwide with the advances in technologies such as Digital Multimedia Broadcasting (DMB), Digital Video Broadcasting - Handheld (DVB-H) and MediaFLO. On the other hand 3DTV is a new approach to watching TV, introducing the third dimension for a more realistic and interactive experience. With the merge of these two technologies it will be possible to have 3DTV products and services based on portable platforms with switchable 2D/3D autostereoscopic displays. The paper presents the European Mobile3DTV project approach toward achieving such a merge. The project specifically addresses the mobile 3DTV delivery over DVB-H system. It develops a technology demonstration system comprising suitable stereo-video content-creation techniques; efficient, scalable and flexible stereo-video encoders with error resilience and error-concealment capabilities, tailored for robust transmission over DVB-H; and also the corresponding stereo-video decoders and players working on a portable terminal device equipped with an autostereoscopic display.
MOBILE 3DTV technology demonstrator based on OMAP 3430

We present receiver-side components of the mobile 3DTV technology being developed. We focus on the DVB-T/H receiving module, the 3D video decoder and player, and the auto-stereoscopic display. These three components have been integrated within the OMAP 3430 EVM. We have developed software decapsulator which decapsulates MPE-FEC tables out of MPEG2 transform streams into RTP to feed the H.264 based video decoder modified to decode side-by-side stereo video. An interface card has been developed to interface a parallax barrier auto-stereoscopic display to the system. We provide details about the implementation of these modules and focus on some image processing techniques aimed at correct display of the stereo video content.
Image based rendering technique via sparse representation in shearlet domain

In this paper we propose a method for reconstructing a densely sampled light field from a given sparse set of perspective views from rectified cameras without an explicit estimation of the scene depth. The desired intermediate views are synthesized by inpainting of epipolar-plane images, utilizing their sparsity in the shearlet domain. For the purpose of shearlet-domain representation, compactly supported shearlets have been constructed using different directional filters for different scales in an attempt to provide better directional selectivity at lower scales. The reconstruction procedure with shearlet-domain sparsity condition is implemented through an iterative thresholding algorithm. The performance of the method is quantified by tests on synthetic and real visual data and compared favorably against depth-image based rendering.
Fixed-pattern noise suppression in low-sensing environment of Time-of-Flight devices

In this paper, we emphasize the importance of fixed-pattern noise (FPN) that occurs in Time-of-Flight (ToF) devices that operate in the so-called low-sensing environment. We propose a method for designing FIR filters that can be used for suppressing the FPN. We illustrate by means of two experiments the importance of dealing with the FPN, before conventional denoising algorithms are applied.
Decoding complexity reduction in projection-based light-field 3D displays using self-contained HEVC tiles

The goal of this work is to provide a low complexity video decoding solution for High Efficiency Video Coding (HEVC) streams in applications where only a region of the video frames is needed to be decoded. This paper studies the problem of creating self-contained (i.e., independently decodable) partitions in the HEVC streams. Further, the requirements for building self-contained regions are described, and an encoder-side solution is proposed based on HEVC tile feature. A particular application of self-contained tiles targets the type of light-field 3D displays, which employ a dense set of optical engines to recreate the light field. Correspondingly, such 3D displays require a dense set of input views and therefore the partial decoding of bitstreams helps providing less complex and consequently real-time decoding and processing. The simulation results show a significant increase in decoding speed at the cost of a minor increase in storage capacity.
Powerline interference suppression in high-resolution ECG

The efficacy of four powerline interference suppression methods was tested for application in high-resolution electrocardiogram (ECG). The goal was minimal distortion of the original signal micro-potential waveform, combined with maximum noise reduction. Simulated low amplitude His-bundle potentials were used for the evaluation. Several objective parameters were measured, such as mean square error and mean absolute error. The methods were applied for His-bundle potentials recovery from real surface ECG signals. Synchronous intracardiac signals with well expressed His potential were recorded and used for reference. Modified time-domain subtraction and regression subtraction methods were found superior to notch filters and spectral interpolation.
Efficient cost volume sampling for plane sweeping based multiview depth estimation

Plane sweeping is an increasingly popular algorithm for generating depth estimates from multiview images. It avoids image rectification, and can align the matching process with slanted surfaces, improving accuracy and robustness. However, the size of the search space increases significantly when different surface orientations are considered. We present an efficient way to perform plane sweeping without individually computing reprojection and similarity metrics on image pixels for all cameras, all orientations and all distances. The procedure truly excels when the amount of views is increased and scales efficiently with the number of different plane orientations. It relies on approximation to generate the costs, but the differences are shown to be small. In practice, it provides results equivalent to conventional matching but faster, making it suitable for applying in many existing implementations.
Denoising the electrocardiogram from electromyogram artifacts by combined transform-domain and dynamic approximation method

A method for electromyogram (EMG) artifact suppression in electrocardiogram (ECG) recordings is presented. In an attempt to improve the traditional compromise between efficient EMG artifact suppression and preservation of the ECG waveform, the method combines a dynamic approximation filtering working in the QRS complexes areas, with a transform domain denoising of the segments outside them. The switching between the two procedures is controlled by the ECG signal slew rate. The results obtained show a virtual preservation of the QRS amplitudes and a considerable reduction of the EMG artifact.
Signal Processing Problems and Algorithms in Display Side of 3DTV

Two important signal processing problems in the display side of a holographic 3DTV are the computation of the diffraction field of a 3D object from its abstract representation, and determination of the best display configuration to synthesize some intended light distribution. To solve the former problem, we worked on the computation of 1D diffraction patterns from discrete data distributed over 2D space. The problem is solved using matrix pseudo-inversion which dominates the computational complexity. Then, the light field synthesis problem by a deflectable mirror array device (DMAD) is posed as a constrained linear optimization problem. The formulation makes direct application of common optimization algorithms quite easy. The simulations indicate that developed methods are promising.
Opengl-Based Control of Semi-Active 3D Display

We present a system for 3D visualisation, which combines user-tracking, used by displays with steerable optics, with generation of multiple views, typical for displays with fixed optical filter. Instead of eye-tracking, typical for the user- tracking approach, we propose a less computationally demanding head tracking, based on face detection. We investigate if the precise delivery of different images to each eye of the observer can be handled by the fixed optics of a multiview 3D display, and if continuous head parallax can be achieved.
A near least squares method for image decimation

This paper introduces an image decimation technique based on the use of a near least-squares criterion that makes a proper compromise between the L/sub 2/ and l/sub 2/ norm minimization cases. The theory of orthogonal projections is related to the derivation of a computationally efficient decimation structure possessing good antialiasing properties. It is shown how this structure can be realized by the transposed Farrow structure when using piece-wise polynomial basis functions. It is shown, by means of examples, that with a considerably lower computational complexity the proposed structure provides practically the same quality for the restored images as the best existing structures.
Transform domain similarity measures in stereo matching

A Fourier-domain representation of an image exhibits a property where a translation of the image is included in the phase term. This property extends to the Discrete Cosine Transform, where the translation is encoded in the signs of the coefficients. An interpretation of this property for use as a similarity measure in local stereo matching is explored with an efficient way of comparing the transformed blocks to generate a dense disparity map. The method is empirically demonstrated to work also with the Haar wavelet transform, which offers faster computation and improved quality. Results show that presented transform based similarity measures provide better disparity estimates than box aggregated Sum of Absolute Differences and the Census transform when using the percentage of bad pixels as the quality measure. In terms of mean squared error, they achieve better results than SAD but are marginally below Census. The simplicity of making the comparisons results in good scaling with the number of disparity estimates, making the suggested method perform better than SAD also computationally.
Fixed-Pattern Noise Modeling and Removal in Time-of-Flight Sensing

In this paper, we discuss the modeling and removal of fixed-pattern noise (FPN) in photonic mixture devices employing the time-of-flight (ToF) principle for range measurements and scene depth estimation. We present a case that arises from low-sensing (LS) conditions caused by either external factors related to scene reflectivity or internal factors related to the power and operation mode of the sensor or both. In such a case, the FPN becomes especially dominating and invalidates previously adopted noise models, which have been used for removal of other noise contaminations in ToF measurements. To tackle LS cases, we propose a noise model specifically addressing the presence of FPN and develop a relevant FPN removal procedure. We demonstrate, by experiments with synthetic and real-world data, that the proper modeling and removing of FPN is substantial for the subsequent Gaussian denoising and yields accurate depth maps comparable to the ones obtainable in normal operating mode.
3DTV Broadcasting and Distribution Systems

In this paper, the authors present three-dimensional television (3DTV) broadcasting and distribution systems that are employed to deliver a pair of stereoscopic images to mobile users, as well as users at home. First, mobile 3DTV systems and services based on DMB and DVB-H are respectively introduced. Second, fixed and high-definition 3DTV systems and services based on terrestrial digital broadcasting are described along with an introduction of experimental 3DTV services in Korea. To be specific, the authors summarize 3DTV systems from the viewpoints of target services, system and user requirements, system configurations, broadcasting trials, related standards, and technical challenges.