Vaclav Ricny

A Novel Metric for H.264/AVC No-Reference Quality Assessment

The article desribes a metric for H.264/AVC compressed video quality evaluation, which is being developed by our group. The metric operates on the encoded bitstream only. It uses the data directly present in the bitstream (or just entropy coded). No pixel decoding should be necessary, which will result in low computational complexity, and cosequently the possibility to analyze several bitstreams simultaneously. In this article, we describe one part of the system which has already been implemented -the feature extractor. A simple analysis is done to demonstrate the variability of the selected parameters used for evaluation.

Measuring flying object velocity with CCD sensors

An autonomous optoelectronic method of measuring the flying objects track velocity vector (TVV) using digital signal two-line CCD sensors has been developed and simulated at the Department of Radioelectronics at the Faculty of Electrical Engineering of the Technical University of Brno, Czech Republic. The principle of the method, the computer simulation of measuring device operations, the application of statistic estimates for the precision of values measured and the presentation of the results achieved are described.<<ETX>>

Estimating PSNR without reference for real H.264/AVC sequence intra frames

The paper describes a novel metric for video quality measurement. The metric is capable of estimating peak signal-to-noise ratio (PSNR) values of pictures in compressed bit streams conforming to the H.264/AVC standard. It is designed and has been tested for intra predicted pictures with varying encoder settings. The metric uses an artificial neural network to estimate PSNR examining the compressed bit stream only. In other words, we do not need to decode the actual pixels within the pictures being evaluated.

Simulated testing of the interferences influence on the DVB-T signal

This paper deals with the testing and assessment of the interferences influence on the DVB-T signals transmitted over the simulated AWGN transmission channel. All experiments were realized in a simulated laboratory environment for typical DVB-T system and channel coding parameters and variable signal levels of the main and disturbing (interfering) signals. Briefly commented results of these measurements are presented.

Fast method for reconstruction of 3D coordinates

The paper deals with the reconstruction of spatial coordinates of an arbitrary point from a scene using two monochromatic images which are in general relation. These two images can be created for example by a stereo camera in practical applications. Calculation is based on the perspective geometry. Search of the point features in each of these images is a fundamental building step to find image correspondence in this procedure. An algorithm for fast elimination of false correspondences which could devastate the scene reconstruction was designed. Well known mathematic relation is used to obtain the fundamental matrix and then reconstruct the 3D coordinates of feature points. Acquisition of 3D coordinates of points in the scene for which it is difficult to find correspondences is more complicated. In the paper, we have proposed a method based on utilization of the relation between the selected point and near features points. The performed experiments confirmed usability of designed procedure.

Simulation and experimental testing of the DVB-T broadcasting in the SFN networks

This paper deals with the transmission of the digital television signal according to the DVB-T standard in SFN network and fixed reception. The laboratory transmission system for simulated broadcasting based on R&S RF test and measurement equipments is presented. The results of bit-error rates and S/N ration in the channel of simulated DVB-T broadcasting in SFN using two transmitters and SFN echo interference are presented and discussed with the theory.

Temporal aspects of scoring in the user based quality evaluation of HD video

The paper deals with the temporal properties of a scoring session when assessing the subjective quality of full HD video sequences using the continuous video quality tests. The performed experiment uses a modification of the standard test methodology described in ITU-R Rec. BT.500. It focuses on the reactive times and the time needed for the user ratings to stabilize at the beginning of a video sequence.

Modulator imperfections and I/Q errors influence on the DVB-T signal

This paper deals with the modulator imperfections and I/Q errors influence on the DVB-T signal and its spectrum and I/Q constellation analysis. Theoretical backgrounds of the Amplitude Imbalance, Phase Error and Carrier Suppression effects are summarized in the paper. Then the practical results measured in the laboratory environment are compared with the theoretical assumed impacts on Modulation Error Rate from the I/Q constellation and Bit Error Rates before and after Viterbi decoding in DVB-T signal decoding.

Extending of the Kinect device functionality and the corresponding database

This paper deals with a creation of the RGB-D database by using Microsoft Kinect device. One of the main uses of Kinect is measurement and subsequent creation the so-called depth maps of the 3D scenes. The maps obtained by Kinect can be improved. Existence of databases suitable for the experiment is very important for research. One of the possible research directions is use of infrared version of the investigated scene for improvement of the depth map. However, the databases of the Kinect data which would contain the corresponding infrared images do not exist. Therefore, our aim was to create such database. We want to increase the usability of the database by adding stereo images. Moreover, the same scenes were captured by Kinect v2. It was also investigated the impact of simultaneous use Kinect v1 and Kinect v2 to improve depth map investigated the scene. The database contains sequences of objects on turntable and simple scenes containing several objects.

The estimation of a depth map using spatial continuity and edges

This paper deals with creating depth maps from two images. The initial map is created using the sum of the absolute differences of the each image points neighborhood. Many discontinuities are in this map. Therefore, we have to use some approach for its improvement. The proposed method utilizes a combination of a few approaches. The first approach is based on the assumption of continuity of the depth map in rows and utilizing information about edges in images. We designed rules for filling zero areas in the initial depth map. The second step uses disparity of significant points found in zero areas. The significant points are found by the algorithm Speeded Up Robust Features (SURF). The applicability of the proposed method is demonstrated on a few images from Middlebury Stereo Datasets. In the future, we will execute subjective tests for examining the influence of the depth map to the evaluation of the spatial effect. The proposed methods will be used as tool for depth maps generation with various quality.