38,026 research outputs found
Optimization for automated assembly of puzzles
The puzzle assembly problem has many application areas such as restoration and reconstruction of archeological findings, repairing of broken objects, solving jigsaw type puzzles, molecular docking problem, etc. The puzzle pieces usually include not only geometrical shape information but also visual information such as texture, color, and continuity of lines. This paper presents a new approach to the puzzle assembly problem that is based on using textural features and geometrical constraints. The texture of a band outside the border of pieces is predicted by inpainting and texture synthesis methods. Feature values are derived from these original and predicted images of pieces. An affinity measure of corresponding pieces is defined and alignment of the puzzle pieces is formulated as an optimization problem where the optimum assembly of the pieces is achieved by maximizing the total affinity measure. An fft based image registration technique is used to speed up the alignment of the pieces. Experimental results are presented on real and artificial data sets
Artificial Substrate and Coral Reef Restoration: What Do We Need to Know to Know What We Need
To use artificial substrate effectively in coral reef restoration certain basic knowledge is required: (1) what is the artificial substrate expected to accomplish relative to the goals of the restoration effort and (2) what are the expected interactions of the selected substrate’s composition, texture, orientation, and design with the damaged environment and the biota of interest. Whereas the first point is usually clear, at least in general terms, the second is not. In this review, we examine: the functions of artificial substrate in restoration and some of the physical (i.e., composition; surface texture; color and chemistry; and design in terms of profile, shelter, shading, size and configuration, settlement attractants, and stability) and environmental factors (i.e., temperature, light sedimentation, surround biota, hydrodynamics, depth, and temporal effects) affecting these functions. We conclude that until substantial additional research is accomplished, the use of artificial substrate in coral reef restoration will remain a ‘best guess’ endeavor. Areas requiring additional research are identified and some potentially promising lines of inquiry are suggested
Division Gets Better: Learning Brightness-Aware and Detail-Sensitive Representations for Low-Light Image Enhancement
Low-light image enhancement strives to improve the contrast, adjust the
visibility, and restore the distortion in color and texture. Existing methods
usually pay more attention to improving the visibility and contrast via
increasing the lightness of low-light images, while disregarding the
significance of color and texture restoration for high-quality images. Against
above issue, we propose a novel luminance and chrominance dual branch network,
termed LCDBNet, for low-light image enhancement, which divides low-light image
enhancement into two sub-tasks, e.g., luminance adjustment and chrominance
restoration. Specifically, LCDBNet is composed of two branches, namely
luminance adjustment network (LAN) and chrominance restoration network (CRN).
LAN takes responsibility for learning brightness-aware features leveraging
long-range dependency and local attention correlation. While CRN concentrates
on learning detail-sensitive features via multi-level wavelet decomposition.
Finally, a fusion network is designed to blend their learned features to
produce visually impressive images. Extensive experiments conducted on seven
benchmark datasets validate the effectiveness of our proposed LCDBNet, and the
results manifest that LCDBNet achieves superior performance in terms of
multiple reference/non-reference quality evaluators compared to other
state-of-the-art competitors. Our code and pretrained model will be available.Comment: 14 pages, 16 figure
A Joint 3D-2D based Method for Free Space Detection on Roads
In this paper, we address the problem of road segmentation and free space
detection in the context of autonomous driving. Traditional methods either use
3-dimensional (3D) cues such as point clouds obtained from LIDAR, RADAR or
stereo cameras or 2-dimensional (2D) cues such as lane markings, road
boundaries and object detection. Typical 3D point clouds do not have enough
resolution to detect fine differences in heights such as between road and
pavement. Image based 2D cues fail when encountering uneven road textures such
as due to shadows, potholes, lane markings or road restoration. We propose a
novel free road space detection technique combining both 2D and 3D cues. In
particular, we use CNN based road segmentation from 2D images and plane/box
fitting on sparse depth data obtained from SLAM as priors to formulate an
energy minimization using conditional random field (CRF), for road pixels
classification. While the CNN learns the road texture and is unaffected by
depth boundaries, the 3D information helps in overcoming texture based
classification failures. Finally, we use the obtained road segmentation with
the 3D depth data from monocular SLAM to detect the free space for the
navigation purposes. Our experiments on KITTI odometry dataset, Camvid dataset,
as well as videos captured by us, validate the superiority of the proposed
approach over the state of the art.Comment: Accepted for publication at IEEE WACV 201
- …