Unsupervised offline video object segmentation using object enhancement and region merging

Content-based representation of video sequences for applications such as MPEG-4 and MPEG-7 coding is an area of growing interest in video processing. One of the key steps to content-based representation is segmenting the video into a meaningful set of objects. Existing methods often accomplish this through the use of color, motion, or edge detection. Other approaches combine several features in an effort to improve on single-feature approaches. Recent work proposes the use of object trajectories to improve the segmentation of objects that have been tracked throughout a video clip. This thesis proposes an unsupervised video object segmentation method that introduces a number of improvements to existing work in the area. The initial segmentation utilizes object color and motion variance to more accurately classify image pixels to their best fit region. Histogram-based merging is then employed to reduce over-segmentation of the first frame. During object tracking, segmentation quality measures based on object color and motion contrast are taken. These measures are then used to enhance video objects through selective pixel re-classification. After object enhancement, cumulative histogram-based merging, occlusion handling, and island detection are used to help group regions into meaningful objects. Objective and subjective tests were performed on a set of standard video test sequences which demonstrate improved accuracy and greater success in identifying the real objects in a video clip compared to two reference methods. Greater success and improved accuracy in identifying video objects is first demonstrated by subjectively examining selected frames from the test sequences. After this, objective results are obtained through the use of a set of measures that aim at evaluating the accuracy of object boundaries and temporal stability through the use of color, motion and histogram

A proposal for dependent optimization in scalabale region-based coding systems

We address in this paper the problem of optimal coding in the framework of region-based video coding systems, with a special stress on content-based functionalities. We present a coding system that can provide scaled layers (using PSNR or temporal content-based scalability) such that each one has an optimal partition with optimal bit allocation among the resulting regions. This coding system is based on a dependent optimization algorithm that can provide joint optimality for a group of layers or a group of frames.Peer ReviewedPostprint (published version

Visual Importance-Biased Image Synthesis Animation

Present ray tracing algorithms are computationally intensive, requiring hours of computing time for complex scenes. Our previous work has dealt with the development of an overall approach to the application of visual attention to progressive and adaptive ray-tracing techniques. The approach facilitates large computational savings by modulating the supersampling rates in an image by the visual importance of the region being rendered. This paper extends the approach by incorporating temporal changes into the models and techniques developed, as it is expected that further efficiency savings can be reaped for animated scenes. Applications for this approach include entertainment, visualisation and simulation

Application of digital interferogram evaluation techniques to the measurement of 3-D flow fields

A system for digitally evaluating interferograms, based on an image processing system connected to a host computer, was implemented. The system supports one- and two-dimensional interferogram evaluations. Interferograms are digitized, enhanced, and then segmented. The fringe coordinates are extracted, and the fringes are represented as polygonal data structures. Fringe numbering and fringe interpolation modules are implemented. The system supports editing and interactive features, as well as graphic visualization. An application of the system to the evaluation of double exposure interferograms from the transonic flow field around a helicopter blade and the reconstruction of the three dimensional flow field is given

LAR Video: Hierarchical Representation for Low Bit-Rate Color Image Sequence Coding

LAR video is a low complexity system for low bit-rate color image sequence encoding. It aims to propose a joint solution for coding and representation of the frame content. In particular, it allows to provide a compressed description of both chromatic components and motion information at a region level without region partition encoding. Initialy proposed in the LAR coder, used principle has proved to be efficient for still color image encoding. Resulting from a hierarchical spatio-temporal segmentation, a Partition Tree (PT) is transmitted to the decoder with a controlled coding cost. Presented results show interesting performances considering both content representation and compression ratios

Survey of Object Detection Methods in Camouflaged Image

Camouflage is an attempt to conceal the signature of a target object into the background image. Camouflage detection methods or Decamouflaging method is basically used to detect foreground object hidden in the background image. In this research paper authors presented survey of camouflage detection methods for different applications and areas