Median filter

About: Median filter is a research topic. Over the lifetime, 12479 publications have been published within this topic receiving 178253 citations.

Quality improving techniques for free-viewpoint DIBR

Abstract: Interactive free-viewpoint selection applied to a 3D multi-view signal is a possible attractive feature of the rapidly developing 3D TV media. This paper explores a new rendering algorithm that computes a free-viewpoint based on depth image warping between two reference views from existing cameras. We have developed three quality enhancing techniques that specifically aim at solving the major artifacts. First, resampling artifacts are filled in by a combination of median filtering and inverse warping. Second, contour artifacts are processed while omitting warping of edges at high discontinuities. Third, we employ a depth signal for more accurate disocclusion inpainting. We obtain an average PSNR gain of 3 dB and 4.5 dB for the 'Breakdancers' and 'Ballet' sequences, respectively, compared to recently published results. While experimenting with synthetic data, we observe that the rendering quality is highly dependent on the complexity of the scene. Moreover, experiments are performed using compressed video from surrounding cameras. The overall system quality is dominated by the rendering quality and not by coding.

Method and system for noise management for spatial processing in digital image/video capture systems

Abstract: A computer-implemented method for noise management in a digital image system measures noise levels of pixel data. The noise levels are adjusted with at least one of an intensity gain setting, a spatial gain setting, and a global gain setting to calculate noise adaptive thresholds for use during spatial processing of the pixel data.

Detail-preserving adaptive conditional median filters

Abstract: We propose a conditional median filter that is able to preserve significantly more image detail than the conventional median filter when suppression of impulsive noise is desired. It does so by means of bypassing filtering when the local signal variation is below an adaptively adjusted threshold. Another advantage of our algorithm is that it is simple to implement and it can be used with any of the available fast median filter algorithms. In addition, it can be easily integrated into existing median filter hardware. We compare the complexity of our algorithm with that of another proposed algorithm with similar filtering objectives. The performance of the new algorithm on real images is compared to that of median and center-weighted median filters.

System for the removal of impulsive noise in image sequences

Abstract: This paper presents a system for the restoration of image sequences that are degraded by impulsive noise such as scratches or dropouts. The proposed system uses a multilevel block matching algorithm to estimate the motion between frames and considers the use of an impulsive noise detector to improve the quality of restoration as compared to a global median operation. The detector considers the temporal continuity of motion compensated image information and makes a decision as to whether a suspected discontinuity is due to an impulsive distortion or occlusion in the sequence. When a corrupted portion of the image is detected a motion compensated median filter is used to remove the distortion. The paper introduces an extended multistage filter for image sequence processing. It is found that the use of the detector cannot adversely affect the filtered image when compared to the globally filtered image, and the detail preservation is generally better. The speed of processing is also increased since the number of median filtering operations is considerably reduced.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.