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Due to its robustness and computational efficiency, the mean shift based algorithms have achieved considerable success in object tracking. Color histogram is used in these algorithms to represent the target model. The Bhattacharyya coefficient is employed as the similarity measure to evaluate the difference between the model and the target candidates. In practice, there exist some limits in these...
We propose a non-homogeneous conditional random field built over an adjacency graph of superpixels for contextual classification of high-resolution satellite images. By introducing the contextual histogram descriptor, our model includes spatially dependent unary and pairwise potentials that capture contextual interactions of the data as well as the labels. This results the non-homogeneity of the fields...
Bilateral filtering provides a scheme for non-iterative edge-preserving smoothing, but the results could be strongly affected by the presence of outliers. In this paper we develop a robust bilateral filter for color images, and in order to achieve this we propose to improve the bilateral filtering technique by using Ordered Weighted Averaging operators. We adopt a fuzzy logic based approach: if the...
We demonstrate composable volumetric lenses as interpretational tools for geological visualization. The lenses provide a constrained focus region that provides alternative views of datasets to the user while maintaining the context of surrounding features. Our rendering method is based on run-time composition of GPU shader programs that implement per-fragment clipping to lens boundaries and surface...
Augmented reality (AR) displays often reduce the visual capabilities of the user. This reduction can be measured both objectively and through user studies. We acquired objective measurements with a color meter and conducted two user studies for each of two key measurements. First was the combined effect of resolution and display contrast, which equate to the visual acuity and apparent brightness....
In this paper, we propose a new network drawing tool, which considers the direction of traffic on Autonomous System level (AS-level) networks. Almost all traditional network graph drawing tools consider only the connections between nodes and disregard the direction of traffic. Moreover, these tools tend to draw complicated pictures. The reasons for this are that AS-level network structures are very...
Based on the thin-lens imaging model in geometric optics, we present a parameterized imaging effect model on graphics processor units, which needs only one pass model rendering and one pass post-processing. This model can be used to implement fast depth of field effect on a given model without changing any original code. The experiment demonstrates that our post-processing model costs only from 0...
Similarity of images in content-based image retrieval (CBIR) is a subjective measure varying by the user, and requires tuning according to the user's preference. Another issue in CBIR is the need of partial image matching. Structural modeling of the images can be promising in finding a small query image within a large database image. In this work, a graph-based image modeling which assigns image regions...
We tested users' depth perception of virtual objects in our mobile augmented reality (AR) system in both indoor and outdoor environments using a depth matching task. The indoor environment is characterized by strong linear perspective cues; we attempted to re-create these cues in the outdoor environment. In the indoor environment, we found an overall pattern of underestimation of depth that is typical...
According to the Retinex theory, the color of an object is jointly decided by its reflecting ability to three independent wave-length lights-lights of short, medium, and long wave. The reflecting ability of the object in a certain wave band is an immanence nature which does not rely on lamp-house itself. In the Retinex model, the brightness values of each pixel have been replaced by an ratio of the...
In this paper we propose a color image segmentation algorithm based on visible color difference and block-based region growing techniques. Firstly, the original image is divide into image blocks which are not overlapped; then, the mean and variance of each image black was calculated in CIEL*a*b* color space, and the image blocks were divided into homogeneous color blocks and texture blocks by the...
Though FCM has long been widely used in image segmentation, it yet faces several challenges. Traditional FCM needs a laborious process to decide cluster center number by repetitive tests. Moreover, random initialization of cluster centers can let the algorithm easily fall onto local minimum, causing the segmentation results to be suboptimal. Traditional FCM is also sensitive to noise due to the reason...
Performance of traditional content-based image retrieval systems is far from userpsilas expectation due to the ldquosemantic gaprdquo between low-level visual features and the richness of human semantics. In attempt to reduce the ldquosemantic gaprdquo, this paper introduces a new effective image retrieval approach-the multi-step queries strategy-that facilitates retrieval of semantically similar...
In this paper, we proposed a scaling algorithm based on inverse square law for bilinear interpolation. In order to use inverse square law, we modify bilinear interpolation. The image quality was compared with those of the conventional image scaling algorithms with Matlab. From the result, proposed algorithm has good quality and high sharpness. Our proposed algorithm uses 12 pixels of original image...
Feature extraction algorithm is a very important component of any retrieval scheme. We propose M-band Wavelet Transform based feature extraction algorithm in this paper. The MtimesM sub-bands are used as primitive features, over which energies computed in a neighborhood are taken as the features for each pixel of the image. These features are clustered using FCM to obtain image signature for similarity...
Multimedia fingerprinting, also know as robust/perceptual hashing and replica detection is an emerging technology that can be used as an alternative to watermarking for the efficient Digital Rights Management (DRM) of multimedia data. Two fingerprinting approaches are reviewed in this paper. The first is an image fingerprinting technique that makes use of color and texture descriptors,R-trees and...
This paper presents a method for the detection of obstacles in the trajectory of unmanned ground vehicle (UGV). To detect obstacles, two different sensors are used, i.e., a vision sensor and a scanning lidar. While lidar measures the precise distance of the object, it cannot detect low objects due to its constant scanning height and angle. In contrast, vision sensor provides 2-D scenery information...
In the content-based image retrieval systems such images what are similar to a given image can be retrieved, that consist some features or of the whole image, either of the homogeneous connected regions of the image. If the creation of the applied feature vectors is made by the homogeneous connected regions, then there is a great significance of the determination process of the objects. In this paper...
This paper proposes an image retrieval technique using local texture features based on Fourier transform. The proposed texture features represent the spatial correlation of texture patterns more effectively with less size of the feature vector, compared to the existing ones. By experimental results, it has been shown that the proposed method achieves improved retrieval results over the existing methods.
Computational scheme for comparison, color analysis and segmentation of images is proposed in this paper. First of all, two growing unsupervised learning algorithms are introduced. They create the so called compressed information model (CIM) of the image that replaces the original ldquoraw datardquo (the RGB pixels) with a smaller number of neurons. Then two main features are extracted from the CIM,...
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