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(1 - 3 of 3)
- Title
- VIEW SYNTHESIS OF THREE DIMENSIONAL VIDEOS USING VIDEO PLUS DEPTH
- Creator
- Loghman, Maziar
- Date
- 2012-07-02, 2012-05
- Description
-
This thesis investigates the use of segmentation in view synthesis for three- dimensional video. View synthesis is the process of generating...
Show moreThis thesis investigates the use of segmentation in view synthesis for three- dimensional video. View synthesis is the process of generating novel views of a scene, using set of views as the reference. Recently, several techniques have been suggested that use the depth maps for rendering virtual views. However, inaccuracy in depth maps causes annoying visual artifacts in depth-based view synthesis. This thesis presents an e cient depth image-based rendering technique based on segmentation using multi-level thresholding. In the proposed algorithm, rst all the images are segmented according to the depth and the pixels belonging to di erent objects are warped and blended independently. Based on multi-level thresholding, an algorithm for nding the ghost contour pixels is provided which simpli es the computations. A novel method for inpainting for disocclusions is introduced which uses the segmented images to nd the associated background boundary pixels. The experimental results show that the proposed algorithm improves the PSNR of the synthesized views up to 0:68 dB for the multi-view video test sequences and eliminates the annoying artifacts.
M.S. in Electrical Engineering, May 2012
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- Title
- Multi-Resolution Depth Estimation Using Modified Census Transform for Advanced Driver Assistance Systems
- Creator
- Loghman, Maziar, Mesmakhosroshahi, Maral, Kim, Joohee
- Date
- 2018-01-04, 2017-09-05
- Description
-
A computer-implemented depth estimation method based on non-parametric Census transform with adaptive window patterns and semi-global...
Show moreA computer-implemented depth estimation method based on non-parametric Census transform with adaptive window patterns and semi-global optimization. A modified cross-based cost aggregation technique adaptively creates the shape of the cross for each pixel distinctly. In addition, a depth refinement algorithm fills holes within the estimated depth map using the surrounding background depth pixels and sharpens the object boundaries by exerting a trilateral filter to the generated depth map. The trilateral filter uses the curvature of pixels as well as texture and depth information to sharpen the edges.
Sponsorship: Illinois Institute of Technology
United States Patent
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- Title
- STEREO-BASED DEPTH MAP PROCESSING: ESTIMATION AND REFINEMENT
- Creator
- Loghman, Maziar
- Date
- 2016, 2016-12
- Description
-
During the past decade, research in 3D video has become a hot topic owing to advancements in both hardware and software. Amongst different...
Show moreDuring the past decade, research in 3D video has become a hot topic owing to advancements in both hardware and software. Amongst different methods proposed for representing 3D data, multi-view video plus depth (MVD) format has gained a lot of attention. Most of such 3D algorithms rely on a per-pixel depth representation of the scene called a depth map. Depth maps are very useful for rendering virtual views and have lead to advancements in 3D compression algorithms. Generating an accurate and dense depth map is one of the important prerequisite for many 3D video applications. In this thesis, we highlight the following major problems in MVD. * Depth map estimation * Depth map refinement * Depth map coding In order to generate an accurate depth map, we propose a method based on Census transform with adaptive window patterns and semi-global optimization. A modified cross-based cost aggregation technique is proposed which helps to calculate a more reliable depth map. In order to further enhance the quality of the generated depth map, a novel multi-resolution anisotropic diffusion based algorithm is presented. The proposed depth refinement algorithm computes a dense depth map in which the holes have been filled and the object boundaries are sharpened. The next part of the research is based on depth map coding. In depth map coding, a considerable amount of time is required to investigate the mode decision pro- cess for every block of depth pixels. However, in real-time purposes, we can partially skip the mode selection step. In this thesis, we propose a novel depth intra-coding scheme for 3D video coding based on HEVC standard. The core idea of the proposed method is motivated by the fact that depth maps have specific characteristics that distinguish them from those of color images. By analyzing the reference depth maps based on homogeneousness of different regions, for some particular blocks, the DMM full-RD search is skipped and the mode is selected based on the previous similar tree- blocks. By this means, the time complexity of the encoding process is significantly reduced.
Ph.D. in Electrical Engineering, December 2016
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