Selection of Temporal Aligned Video Frames for Video Stitching Application

Multi-view image/video stitching algorithm is an extensive research area in computer vision and image based rendering. Most researches focus on stitching the images from different views with assumption that those images have been already aligned in temporal domain. However it is not the case in real application. If the images from different views are not aligned in temporal domain, or in another words, not time synchronized, the corresponding feature points or regions will not be located correctly among different views, which will result in ghost objects appearing in the final stitching/rendering result. In this paper, we present an epipolar geometry consistency scoring scheme to guide temporal aligned video frame pair selection for multi-view video stitching application. Essentially, the proposed scheme allows us to determine whether a given pair of video frames is temporally aligned well for video stitching. Experimental results confirm that better video stitching results can be obtained with the proposed scheme in place.published_or_final_versio

An efficient parameterless quadrilateral-based image segmentation method

This paper proposes a general quadrilateral-based framework for image segmentation, in which quadrilaterals are first constructed from an edge map, where neighboring quadrilaterals with similar features of interest are then merged together to form regions. Under the proposed framework, the quadrilaterals enable the elimination of local variations and unnecessary details for merging from which each segmented region is accurately and completely described by a set of quadrilaterals. To illustrate the effectiveness of the proposed framework, we derived an efficient and high-performance parameterless quadrilateral-based segmentation algorithm from the framework. The proposed algorithm shows that the regions obtained under the framework are segmented into multiple levels of quadrilaterals that accurately represent the regions without severely over or undersegmenting them. When evaluated objectively and subjectively, the proposed algorithm performs better than three other segmentation techniques, namely, seeded region growing, K-means clustering and constrained gravitational clustering, and offers an efficient description of the segmented objects conducive to content-based applications. © 2005 IEEE.published_or_final_versio

Explicit contour model for vehicle tracking with automatic hypothesis validation

This paper addresses the problem of vehicle tracking under a single static, uncalibrated camera without any constraints on the scene or on the motion direction of vehicles. We introduce an explicit contour model, which not only provides a good approximation to the contours of all classes of vehicles but also embeds the contour dynamics in its parameterized template. We integrate the model into a Bayesian framework with multiple cues for vehicle tracking, and evaluate the correctness of a target hypothesis, with the information implied by the shape, by monitoring any conflicts within the hypothesis of every single target as well as between the hypotheses of all targets. We evaluated the proposed method using some real sequences, and demonstrated its effectiveness in tracking vehicles, which have their shape changed significantly while moving on curly, uphills roads. © 2005 IEEE.published_or_final_versionThe IEEE International Conference on Image Processing (ICIP 2005), Genoa, Italy, 11-14 September 2005. In Proceedings of IEEE-ICIP, 2005, v. 2, p. 582-58

Shadow detection for vehicles by locating the object-shadow boundary

We introduce in this paper a shadow detection method for vehicles in traffic video sequences. Our method approximates the boundary between vehicles and their associated shadows by one or more straight lines. These lines are located in the image by exploiting both local information (e.g. statistics in intensity differences) and global information (e.g. principal edge directions). The proposed method does not assume a particular lighting condition, and requires no human interaction nor parameter training. Experiments on practical real-world traffic video sequences demonstrate that our method is simple, robust and efficient under traffic scenes with different lighting conditions. Accurate positioning of target vehicles is thus achieved even in the presence of cast shadows.postprin

Super-resolution of faces using texture mapping on a generic 3D model

This paper proposes a novel face texture mapping framework to transform faces with different poses into a unique texture map. Under this framework, texture mapping can be realized by utilizing a generic 3D face model, standard Haar-like feature based detector, active appearance model and pose estimation algorithm. By this texture map, correspondence of every pixel at the face across multiple distinct input images can then be established, which enables super-resolution algorithms to be applied directly on registered texture map to render high resolution faces. This paper details the proposed framework, and illustrates how the proposed super-resolution algorithm works with the help of weighted average and median filters. Convincing experimental results are also presented to validate the effectiveness of the proposed framework and superresolution algorithm. © 2009 IEEE.published_or_final_versio

Motion and edge adaptive interpolation de-interlacing algorithm

This paper presents a new motion and edge adaptive de-interlacing algorithm, which is efficient and artifacts-free. It is novel in the sense that it introduces a way to properly interpolate the two (odd and even) field images according to the information provided by the simplest form of motion detection and edge orientation estimation methods. The proposed algorithm was evaluated by three video sequences, namely, 'Akiyo', 'Silent', 'Foreman'. Experimental results confirm that the proposed algorithm performs, both objectively and subjectively, much better than other similar algorithms. These promising results indicate that the proposed interpolation approach has good potential to realize even better de-interlacing algorithms, if more sophisticated motion detection and edge orientation estimation methods are employed.postprintThe 10th WSEAS international conference on Computers (ICCOMP'06), Athens, Greece, 13-15 July 2006. In Proceedings of ICCOMP, 2006, p. 1030-103

Motion and edge adaptive interpolation de-interlacing algorithm

This paper presents a new motion and edge adaptive de-interlacing algorithm, which is efficient and artifacts-free. It is novel in the sense that it introduces a way to properly interpolate the two (odd and even) field images according to the information provided by the simplest form of motion detection and edge orientation estimation methods. The proposed algorithm was evaluated by three video sequences, namely, 'Akiyo', 'Silent', 'Foreman'. Experimental results confirm that the proposed algorithm performs, both objectively and subjectively, much better than other similar algorithms. These promising results indicate that the proposed interpolation approach has good potential to realize even better de-interlacing algorithms, if more sophisticated motion detection and edge orientation estimation methods are employed.postprintThe 10th WSEAS international conference on Computers (ICCOMP'06), Athens, Greece, 13-15 July 2006. In Proceedings of ICCOMP, 2006, p. 1030-103

Generalized motion and edge adaptive interpolation de-interlacing algorithm

This paper presents a generalized motion and edge adaptive de-interlacing framework, which offers a structured way to develop de-interlacing algorithm. The framework encompasses many typical de-interlacing algorithms, ranging from simple interpolation based algorithms, to more complex edge dependent and motion adaptive algorithms. Based on this framework, we develop a new de-interlacing algorithm which is efficient and artifacts-free. The proposed algorithm was evaluated by five video sequences, namely, "Akiyo", Mother and Daughter", "Silent", "Foreman" and "Stefan". Experimental results confirm that the proposed algorithm performs, both objectively and subjectively, much better than other similar algorithms. These promising results indicate that the proposed framework has good potential for realizing even better de-interlacing algorithms.postprin

Watershed segmentation with boundary curvature ratio based merging criterion

This paper proposes to incorporate boundary curvature ratio, region homogeneity and boundary smoothness into a single new merging criterion to improve the oversegmentation of marker-controlled watershed segmentation algorithm. The result is a more refined segmentation result with smooth boundaries and regular shapes. To pursue a final segmentation result with higher inter-variance and lower intra-variance, an optimal number of segments could be self-determined by a proposed formula. Experimental results are presented to demonstrate the merits of this method.postprintThe 9th IASTED International Conference on Signal and Image Processing (SIP 2007), Honolulu, HI., 20-22 August 2007. In Proceedings of SIP, 2007, p. 7-1

Combined and interacting effects of hand and head movement delays on discrete manual performance in a virtual environment

Transmission delays occur when a virtual environment responds to the hand and head movements of an operator. The effects of hand and head-related delays on discrete manual performance was investigated experimentally and compared. Imposed hand and head-related pure delays equal to or greater than 110 ms and 220 ms, respectively, significantly increased hand Movement Time (MT). The effect of hand-related delays was greater than that of head-related delays of the same magnitude. A regression model describing the combined effects of both delays on MT is reported (R-2 = 0.95). Analyses of the interactions among delays, target width, and distances have shown the need to adopt the traditional classification of delays into (1) control delay, and (2) display delay. The use of this taxonomy and the regression analyses to describe and explain the effects of individual and combined effects of delays on discrete target-reaching task performance in virtual environments are discussed