scholarly journals Joint Geometry and Color Projection-based Point Cloud Quality Metric

2021 ◽  
Author(s):  
Alireza Javaheri ◽  
Catarina Brites ◽  
Fernando Pereira ◽  
Joao Ascenso
Keyword(s):  
Point Cloud ◽  
Pearson Correlation ◽  
Quality Metrics ◽  
Experimental Results ◽  
Reliable Estimate ◽  
Quality Metric ◽  
Joint Geometry ◽  
Objective Quality ◽  
Correlation Performance

Point cloud coding solutions have been recently standardized to address the needs of multiple application scenarios. The design and assessment of point cloud coding methods require reliable objective quality metrics to evaluate the level of degradation introduced by compression or any other type of processing. Several point cloud objective quality metrics has been recently proposed to reliable estimate human perceived quality, including the so-called projection-based metrics. In this context, this paper proposes a joint geometry and color projection-based point cloud objective quality metric which solves the critical weakness of this type of quality metrics, i.e., the misalignment between the reference and degraded projected images. Moreover, the proposed point cloud quality metric exploits the best performing 2D quality metrics in the literature to assess the quality of the projected images. The experimental results show that the proposed projection-based quality metric offers the best subjective-objective correlation performance in comparison with other metrics in the literature. The Pearson correlation gains regarding D1-PSNR and D2-PSNR metrics are 17% and 14.2 when data with all coding degradations is considered.

scholarly journals Joint Geometry and Color Projection-based Point Cloud Quality Metric

2021 ◽  
Author(s):  
Alireza Javaheri ◽  
Catarina Brites ◽  
Fernando Pereira ◽  
Joao Ascenso
Keyword(s):  
Point Cloud ◽  
Pearson Correlation ◽  
Quality Metrics ◽  
Experimental Results ◽  
Reliable Estimate ◽  
Quality Metric ◽  
Joint Geometry ◽  
Objective Quality ◽  
Correlation Performance

Point cloud coding solutions have been recently standardized to address the needs of multiple application scenarios. The design and assessment of point cloud coding methods require reliable objective quality metrics to evaluate the level of degradation introduced by compression or any other type of processing. Several point cloud objective quality metrics has been recently proposed to reliable estimate human perceived quality, including the so-called projection-based metrics. In this context, this paper proposes a joint geometry and color projection-based point cloud objective quality metric which solves the critical weakness of this type of quality metrics, i.e., the misalignment between the reference and degraded projected images. Moreover, the proposed point cloud quality metric exploits the best performing 2D quality metrics in the literature to assess the quality of the projected images. The experimental results show that the proposed projection-based quality metric offers the best subjective-objective correlation performance in comparison with other metrics in the literature. The Pearson correlation gains regarding D1-PSNR and D2-PSNR metrics are 17% and 14.2 when data with all coding degradations is considered.

scholarly journals Template Matching and Matrix Profile for Signal Quality Assessment of Carotid and Femoral Laser Doppler Vibrometer Signals

2022 ◽  
Vol 12 ◽  
Author(s):  
Silvia Seoni ◽  
Simeon Beeckman ◽  
Yanlu Li ◽  
Soren Aasmul ◽  
Umberto Morbiducci ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Quality Assessment ◽  
Real Time ◽  
Template Matching ◽  
Quality Metrics ◽  
Laser Doppler ◽  
Signal Quality ◽  
Laser Doppler Vibrometry ◽  
Quality Metric

Background: Laser-Doppler Vibrometry (LDV) is a laser-based technique that allows measuring the motion of moving targets with high spatial and temporal resolution. To demonstrate its use for the measurement of carotid-femoral pulse wave velocity, a prototype system was employed in a clinical feasibility study. Data were acquired for analysis without prior quality control. Real-time application, however, will require a real-time assessment of signal quality. In this study, we (1) use template matching and matrix profile for assessing the quality of these previously acquired signals; (2) analyze the nature and achievable quality of acquired signals at the carotid and femoral measuring site; (3) explore models for automated classification of signal quality.Methods: Laser-Doppler Vibrometry data were acquired in 100 subjects (50M/50F) and consisted of 4–5 sequences of 20-s recordings of skin displacement, differentiated two times to yield acceleration. Each recording consisted of data from 12 laser beams, yielding 410 carotid-femoral and 407 carotid-carotid recordings. Data quality was visually assessed on a 1–5 scale, and a subset of best quality data was used to construct an acceleration template for both measuring sites. The time-varying cross-correlation of the acceleration signals with the template was computed. A quality metric constructed on several features of this template matching was derived. Next, the matrix-profile technique was applied to identify recurring features in the measured time series and derived a similar quality metric. The statistical distribution of the metrics, and their correlates with basic clinical data were assessed. Finally, logistic-regression-based classifiers were developed and their ability to automatically classify LDV-signal quality was assessed.Results: Automated quality metrics correlated well with visual scores. Signal quality was negatively correlated with BMI for femoral recordings but not for carotid recordings. Logistic regression models based on both methods yielded an accuracy of minimally 80% for our carotid and femoral recording data, reaching 87% for the femoral data.Conclusion: Both template matching and matrix profile were found suitable methods for automated grading of LDV signal quality and were able to generate a quality metric that was on par with the signal quality assessment of the expert. The classifiers, developed with both quality metrics, showed their potential for future real-time implementation.

scholarly journals Image Quality Assessment without Reference by Combining Deep Learning-Based Features and Viewing Distance

2021 ◽  
Vol 11 (10) ◽  
pp. 4661
Author(s):  
Aladine Chetouani ◽  
Marius Pedersen
Keyword(s):  
Image Quality ◽  
Image Quality Assessment ◽  
Feature Vector ◽  
Pearson Correlation ◽  
Image Database ◽  
Viewing Distance ◽  
Quality Metric ◽  
Image Quality Metric ◽  
Fully Connected

An abundance of objective image quality metrics have been introduced in the literature. One important essential aspect that perceived image quality is dependent on is the viewing distance from the observer to the image. We introduce in this study a novel image quality metric able to estimate the quality of a given image without reference for different viewing distances between the image and the observer. We first select relevant patches from the image using saliency information. For each patch, a feature vector is extracted from a convolutional neural network model and concatenated at the viewing distance, for which the quality is predicted. The resulting vector is fed to fully connected layers to predict subjective scores for the considered viewing distance. The proposed method was evaluated using the Colourlab Image Database: Image Quality and Viewing Distance-changed Image Database. Both databases provide subjective scores at two different viewing distances. In the Colourlab Image Database: Image Quality we obtain a Pearson correlation of 0.87 at both 50 cm and 100 cm viewing distances, while in the Viewing Distance-changed Image Database we obtained a Pearson correlation of 0.93 and 0.94 at viewing distance of four and six times the image height. The results show the efficiency of our method and its generalization ability.

scholarly journals Edge Dissimilarity Reduced-Reference Quality Metric with Low Overhead Bitrate

2018 ◽  
Vol 10 (2) ◽  
pp. 631
Author(s):  
Farah Diyana Abdul Rahman ◽  
Dimitris Agrafiotis ◽  
Ahmad Imran Ibrahim
Keyword(s):  
Side Information ◽  
Video Quality ◽  
Low Complexity ◽  
Edge Information ◽  
Quality Metric ◽  
Objective Quality ◽  
Reference Quality ◽  
Edge Based ◽  
Video Quality Metric

In multimedia transmission, it is important to rely on an objective quality metric which accurately represents the subjective quality of processed images and video sequences. Reduced-reference metrics make use of side-information that is transmitted to the receiver for estimating the quality of the received sequence with low complexity. In this paper, an Edge-based Dissimilarity Reduced-Reference video quality metric with low overhead bitrate is proposed. The metric is evaluated by finding the dissimilarity between the edge information of original and distorted sequences. The edge degradation can be detected in this manner as perceived video quality is highly associated with edge structural. Due to the high overhead using the Soergel distance, it is pertinent to find a way to reduce the overhead while maintaining the edge information that can convey the quality measure of the sequences. The effects of different edge detection operator, video resolution and file compressor are investigated. The aim of this paper is to significantly reduce the bitrate required in order to transmit the side information overhead as the reduced reference video quality metric. From the results obtained, the side information extracted using Sobel edge detector maintained consistency throughout the reduction of spatial and temporal down-sample.

scholarly journals AMBIQUAL: Towards a Quality Metric for Headphone Rendered Compressed Ambisonic Spatial Audio

2020 ◽  
Vol 10 (9) ◽  
pp. 3188
Author(s):  
Miroslaw Narbutt ◽  
Jan Skoglund ◽  
Andrew Allen ◽  
Michael Chinen ◽  
Dan Barry ◽  
...  
Keyword(s):  
Service Providers ◽  
Spatial Audio ◽  
Localization Accuracy ◽  
Quality Metric ◽  
Audio Quality ◽  
Listening Tests ◽  
Objective Quality ◽  
Streaming Service ◽  
Quality Assessments

Spatial audio is essential for creating a sense of immersion in virtual environments. Efficient encoding methods are required to deliver spatial audio over networks without compromising Quality of Service (QoS). Streaming service providers such as YouTube typically transcode content into various bit rates and need a perceptually relevant audio quality metric to monitor users’ perceived quality and spatial localization accuracy. The aim of the paper is two-fold. First, it is to investigate the effect of Opus codec compression on the quality of spatial audio as perceived by listeners using subjective listening tests. Secondly, it is to introduce AMBIQUAL, a full reference objective metric for spatial audio quality, which derives both listening quality and localization accuracy metrics directly from the B-format Ambisonic audio. We compare AMBIQUAL quality predictions with subjective quality assessments across a variety of audio samples which have been compressed using the Opus 1.2 codec at various bit rates. Listening quality and localization accuracy of first and third-order Ambisonics were evaluated. Several fixed and dynamic audio sources (single and multiple) were used to evaluate localization accuracy. Results show good correlation regarding listening quality and localization accuracy between objective quality scores using AMBIQUAL and subjective scores obtained during listening tests.

Pemetaan Secara Sistematis Pada Metrik Kualitas Perangkat Lunak

2015 ◽  
Vol 6 (4) ◽  
Author(s):  
Mamluatul Hani’ah ◽  
Yogi Kurniaawan ◽  
Umi Laili Yuhana
Keyword(s):  
Software Quality ◽  
Quality Measurement ◽  
Measurement Model ◽  
Quality Metrics ◽  
Systematic Mapping ◽  
Quality Metric ◽  
Current Trends ◽  
Software Quality Metrics ◽  
Software Quality Models

Abstract. Software quality assurance is one method to increase quality of software. Improvement of software quality can be measured with software quality metric. Software quality metrics are part of software quality measurement model. Currently software quality models have a very diverse types, so that software quality metrics become increasingly diverse. The various types of metrics to measure the quality of software create proper metrics selection issues to fit the desired quality measurement parameters. Another problem is the validation need to be performed on these metrics in order to obtain objective and valid results. In this paper, a systematic mapping of the software quality metric is conducted in the last nine years. This paper brings up issues in software quality metrics that can be used by other researchers. Furthermore, current trends are introduced and discussed.Keywords: Software Quality, Software Assesment, Metric Abstrak. Penjaminan kualitas suatu perangkat lunak merupakan salah satu cara meningkatkan kualitas suatu perangkat lunak. Metrik kualitas perangkat lunak merupakan bagian dari model pengukuran kualitas perangkat lunak. Model kualitas perangkat lunak memiliki jenis yang sangat beragam, sehinggga metrik kualitas perangkat lunak menjadi semakin beragam jenisnya. Beragamnya jenis metrik pengukuran kualitas perangkat lunak memberikan permasalahan pemilihan metrik yang tepat agar sesuai dengan parameter pengukuran kualitas yang diinginkan. Permasalahan yang lain adalah validasi yang harus dilakukan terhadap metrik tersebut agar diperoleh hasil yang obyektif dan valid. Dalam makalah ini akan dilakukan pemetaan sistemastis terhadap metrik pengukuran kualitas perangkat lunak pada sembilan tahun terakhir. Diharapkan dengan pemetaan sistematis akan dapat memunculkan permasalahan-permasalahan pada metrik kualitas perangkat lunak yang dapat digunakan sebagai penelitian untuk peneliti yang lain. Kata Kunci: Kualitas Perangkat Lunak, Penjaminan Perangkat Lunak, Metrik

A novel point cloud quality assessment metric based on perceptual color distance patterns

2021 ◽  
Vol 2021 (9) ◽  
pp. 256-1-256-11
Author(s):  
Rafael Diniz ◽  
Pedro Garcia Freitas ◽  
Mylène Farias
Keyword(s):  
Quality Assessment ◽  
Point Cloud ◽  
State Of The Art ◽  
Perceptual Quality ◽  
Great Effort ◽  
Robust Performance ◽  
Wide Range ◽  
Objective Quality ◽  
Novel Method

In recent years, PCs have become very popular for a wide range of applications, such as immersive virtual reality scenarios. As a consequence, in the last couple of years, there has been a great effort to develop novel acquisition, representation, compression, and transmission solutions for PC contents in the research community. In particular, the development of objective quality assessment methods that are able to predict the perceptual quality of PCs. In this paper, we present an effective novel method for assessing the quality of PCs, which is based on descriptors that extract perceptual color distance-based texture information of PC contents, called Perceptual Color Distance Patterns (PCDP). In this framework, the statistics of the extracted information are used to model the PC visual quality. Experimental results show that the proposed framework exhibit good and robust performance when compared with several state-of-the-art point cloud quality assessment (PCQA) methods.

scholarly journals Iterative Phase-Only Hologram Generation Based on the Perceived Image Quality

2019 ◽  
Vol 9 (20) ◽  
pp. 4457 ◽  
Author(s):  
Haining Yang ◽  
Daping Chu
Keyword(s):  
Image Quality ◽  
Mean Squared Error ◽  
Quality Metrics ◽  
Critical Element ◽  
Image Content ◽  
Quality Metric ◽  
Squared Error ◽  
Image Quality Metrics ◽  
Image Quality Metric

Image quality metrics are a critical element in the iterative Fourier transform algorithms (IFTAs) for the computer generation of phase-only holograms. Conventional image quality metrics such as root-mean-squared error (RMSE) are sensitive to image content and unable to reflect the perceived image quality accurately. This would have a significant impact on the calculation speed and the quality of the generated hologram. In this work, the structure similarity (SSIM) was proposed as an image quality metric in IFTAs due to its ability to predict the perceived image quality in the presence of the white Gaussian noise and its independence on the image content. This would enable IFTAs to terminate when further iterations would no longer lead to improvement in the perceived image quality. As a result, up to 75% of unnecessary iterations were eliminated by the use of SSIM as the image quality metric.

scholarly journals Point Cloud Coding Solutions, Subjective Assessment and Objective Measures: A Case Study

Symmetry ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 1955
Author(s):  
Emil Dumic ◽  
Luis A. da Silva Cruz
Keyword(s):  
Point Cloud ◽  
Point Clouds ◽  
Quality Measures ◽  
Subjective Assessment ◽  
Subjective Quality ◽  
Point Cloud Data ◽  
Cloud Data ◽  
Objective Quality

This paper presents a summary of recent progress in compression, subjective assessment and objective quality measures of point cloud representations of three dimensional visual information. Different existing point cloud datasets, as well as discusses the protocols that have been proposed to evaluate the subjective quality of point cloud data. Several geometry and attribute point cloud data objective quality measures are also presented and described. A case study on the evaluation of subjective quality of point clouds in two laboratories is presented. Six original point clouds degraded with G-PCC and V-PCC point cloud compression and five degradation levels were subjectively evaluated, showing high inter-laboratory correlation. Furthermore, performance of several geometry-based objective quality measures applied to the same data are described, concluding that the highest correlation with subjective scores is obtained using point-to-plane measures. Finally, several current challenges and future research directions on point clouds compression and quality evaluation are discussed.

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