Vision-based applications usually have as input a continuous stream of data. Therefore, it is possible to use the information generated in previous frames to improve the analysis of the current one. In the context of video-based driver-assistance systems, objects present in a scene typically perform a smooth motion through the image sequence. By considering a motion model for the ego-vehicle, i...

In this paper, we propose a spatio-temporal filtering scheme that utilizes motion compensation with multireference frames in H.264 to remove noise. It utilizes the variation of inter mode distributions to detect noise and determine the parameters for spatial filter. In the time domain, a reference pixel is selected from multireference frames according to the motion trajectory and MSE criterion....

In this paper, spatial neighboring pixels are used to deal with blocking and ringing artifacts while temporal neighboring pixels are utilized to remove mosquito and flickering artifacts. To avoid the blurring effect of linear filters, a fuzzy filter is implemented. Fuzzy filter is a specific case of bilateral filters [15], [16]. Fuzzy filters help denoising the artifacts while retaining the sha...

The relative involvement of different temporal frequency-selective filters underlying detection of chromatic stimuli was studied. Diverse spectral stimuli were used, namely flashed blue and yellow light spots, wide bars, and narrow bars. The stimuli were temporally modulated in luminance having constant wavelength. Although the bar-like stimuli apparently reduced the sensitivity at short and lo...

This thesis examines techniques to improve the robustness of automatic speech recognition (ASR) systems against noise distortions. The study is important as the performance of ASR systems degrades dramatically in adverse environments, and hence greatly limits the speech recognition application deployment in realistic environments. Towards this end, we examine a feature compensation approach and...

In this paper, we propose a new video denoising algorithm which uses an efficient wavelet based spatio-temporal filter. The filter first applies 2D discrete wavelet transform (DWT) in horizontal and vertical directions on an input noisy video frame and then applies 1-D discrete cosine transform (DCT) in the temporal direction in order to reduce the redundancies which exist among the wavelet coe...

Abstract. Recently, different models of the statistical structure of natural images have been proposed. Maximizing sparseness, or alternatively temporal coherence of linear filter outputs leads to the emergence of simple cell properties. Taking account of the basic dependencies of linear filter outputs enables modelling of complex cell and topographic properties as well. In this paper, I propos...

The quality of the displayed image during minimal-invasive operations (endoscopy) may be low due to highlights and water vapor in front of the camera lens. In some cases, image processing like temporal color vector median filtering may enhance the visual quality of the images [8]. In this contribution we present a new technique of ordering, filtering and re-ordering of color image pixels that i...

Recently, a new concept for perceptual audio coding was presented, which is based on a prefilter in the encoder and a corresponding post-filter in the decoder, both controlled by a psychoacoustic model. It enables individual selection of spectral and temporal resolutions for irrelevancy reduction and redundancy reduction. This paper addresses problems related to the efficient transmission of th...

We propose a scalable extension of the H.264/AVC video coding standard. To achieve an efficient scalable bit-stream representation of a video sequence, the temporal dependencies between pictures are exploited by using an open-loop subband approach. The related temporal analysis-synthesis filter bank structure is generalized to facilitate an adaptive block-based choice between the motion-compens...