Przemysław Skurowski

Image Quality Assessment Using Phase Spectrum Correlation

This paper presents the method of evaluating the image quality using similarity of images phase spectrum. The authors introduce phase correlation coefficient as an objective measure of an image quality index which is compared to the subjective distortion evaluation using stimulus impairment scale. Artificially distorted images produced by proportional mixing of images phase spectra with a noise were used for testing purposes. The results are the mean correlation coefficient values related to the mean opinion score grades. The obtained relation between human responses and phase correlation is linear.

Synchronization of motion sequences from different sources

The paper describes an algorithm for the synchronization of motion sequences derived with different motion capture (mocap) systems. The algorithm is invented for the temporal matching of the motion represented as angular orientation timeseries obtained with different mocap systems. We employed the PCA to reduce problem to a single dimension, then the algorithm comprises twofold exhaustive search allowing for the precise matching of sequences. The method was verified with both - semi synthetic and real sequences.

Evaluation of IP Transmission Jitter Estimators Using One-Way Active Measurement Protocol (OWAMP)

Network transmission with real-time constraints appears to be very sensitive to the jitter – short time packet delivery delay. In this paper we describe several methods for estimating that phenomenon. We perform quantitative and qualitative analyses for the gathered data using modern measurement tool called OWAMP (one way ping) and stratum 1 Network Time Protocol (NTP) time server.

Functional body mesh representation - a simplified kinematic model

This paper describes Functional Body Mesh a simplified representation of a body kinematic structure intended to form a framework for marker-wise signal processing of recorded motion trajectories of motion capture of virtually any vertebrates. The parent-child and sibling relationships are inferred on a coherence of movement and constancy of distances. There is proposed a GMM based method for inferring FBM segments from the raw motion capture data based on a relationship between the points. For creating groups representing specific body parts we propose an incremental multicriterial clustering algorithm employing Gaussian mixture models. To infer body parts hierarchy we propose utilizing a consensus method.

Reference Data Set for Accuracy Evaluation of Orientation Estimation Algorithms for Inertial Motion Capture Systems

In this paper, we describe the freely available repository, RepoIMU, proposed for the needs of orientation estimation algorithm evaluation for inertial motion capture systems. Such algorithms fuse data from IMU sensors - accelerometer, magnetometer and gyroscope. Although such systems gain in popularity, the evaluation of methods used in their development is still not well covered in literature. In presented repository, unlike many others, signals from IMU sensors combined into easily interpretable kinematic chain are synchronized, and not only cropped to, reference orientation obtained from accurate optical motion capture system.

Saliency map based analysis for prediction of car driving difficulty in Google street view scenes

The paper describes how the saliency maps – computational models of visual attention can be used to predict car driving difficulty. The peak number and areas are analyzed for the images are obtained from Google Street View. As a ground truth the crowd sourced average human responses on the speed and subjective driving difficulty are used.

High Dynamic Range in X-ray Imaging

The article demonstrates the usability of HDR techniques applied to the X-ray images. It is intended for the improvement of diagnostic abilities of the X-ray imaging through the fusion of different exposures obtained with different photon energies (kVp). The article comprises background analysis, proof-of-concept using the generic exposure fusion through the Laplace pyramid and a broad survey of tone mapping techniques. The results of the survey were obtained through the experts systematic quality assessment using an adjective-numerical scale.

Bi-cluster Parallel Computing in Bioinformatics – Performance and Eco-Efficiency

The paper discusses the selected bi-clustering algorithms in terms of energy efficiency. We demonstrate the need for the power aware software development, elaborate bi-clustering methods and applications, and describe the experimental computational cluster with a custom built energy measurement instrumentation.

Automatic IMU sensor characterization using Allan variance plots

We present an automatic method for the evaluation of the noise parameters of IMU devices. The method is a the two-stage optimization problem for polyline regression of the Allan variance in log-log domain. We address the initialization issue and segmentation to identify the existing noises which results in the robustness of the results obtained with the numerical solver.We present an automatic method for the evaluation of the noise parameters of IMU devices. The method is a the two-stage optimization problem for polyline regression of the Allan variance in log-log domain. We address the initialization issue and segmentation to identify the existing noises which results in the robustness of the results obtained with the numerical solver.

Optimizing Orthonormal Basis Bilinear Spatiotemporal Representation for Motion Data

The paper describes an attempt to estimate the optimal division of a number of base vectors between space (shape) and time (trajectory) for bilinear spatio-temporal representation of motion capture data. The spatiotemporal model is a matrix consisting of \(K_s \cdot K_t\) amount of coefficients. In the paper we discuss using of orthonormal spatial and temporal basis: PCA-PCA, DCT-DCT, PCA-DCT and DCT-PCA to represent real MoCap data.