We present a new method to visualize virtual endoscopic views. We propose to flatten the organ by the direct projection of the surface onto a set of cylinders. Two sampling strategies are presented and the introduced ...
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Based on the space spanned by {1, t, , tn-5, sint, cost, t sin t, t cos t}, (n≥5), this paper presents a new kind of uniform splines. These splines are called uniform algebraic-trigonometric splines, which share most...
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Based on the space spanned by {1, t, , tn-5, sint, cost, t sin t, t cos t}, (n≥5), this paper presents a new kind of uniform splines. These splines are called uniform algebraic-trigonometric splines, which share most of the properties as those of the B-splines in the polynomial space. Such splines can encompass conical solenoids, involutes of circles and some other transcendent curves. The subdivision scheme of this new kind of curves is given, and it is verified to be convergent. The subdivision scheme is equal to a series of linear subdividing process, which followed the V.D. property and the convexity preserving property of the splines.
Speed bumps are vertical raisings of the road pavement used to force drivers to slow down to ensure greater safety in traffic. However, these obstacles have disadvantages in terms of efficiency and safety, where the p...
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Speed bumps are vertical raisings of the road pavement used to force drivers to slow down to ensure greater safety in traffic. However, these obstacles have disadvantages in terms of efficiency and safety, where the presence of speed bumps can affect travel time and fuel consumption, cause traffic jams, delay emergency vehicles, and cause vehicle damage or accidents when not properly signaled. Due to these factors, the availability of geolocation information for these obstacles can benefit several applications in Intelligent Transportation System (ITS), such as Advanced Driver Assistance Systems (ADAS) and autonomous vehicles, allowing to trace more efficient routes or alert the driver of the presence of the obstacle ahead. Speed bump detection applications described in the literature employ cameras or inertial sensors, represented by accelerometers and gyroscopes. While camera-based solutions are mature with evaluation in different contextual conditions, those based on inertial sensors do not offer multi-contextual analyses, being mostly simple applications of proof of concept, not applicable in real-world scenarios. For this reason, in this work, we propose the development of a reliable speed bump detection model based on inertial sensors, capable of operating reliably in contextual variations: different vehicles, driving styles, and environments in which vehicles can travel to. For the model development and validation, we collect nine datasets with contextual variations, using three different vehicles, with three different drivers, in three different environments, in which there are three different surface types, in addition to variations in conservation state and the presence of obstacles and anomalies. The speed bumps are present in two different pavement types, asphalt and cobblestone. We use the collected data in experiments to evaluate aspects such as the influence of the placement of the sensors for vehicle data collection and the data window size. Afterwar
An approach for applying a structural texture analysis method to automatic visual inspection of fabric samples in the textile industry is presented. The main steps (image preprocessing, image segmentation, model descr...
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We present the micro- and mid-scale elements of an integrated multi-scalar solution to the 3D recording of rock-art sites in their landscape contexts. The photogrammetry-based solution integrates 3D models across vast...
Autonomous model building is a crucial trend in model based methods like AAMs. This paper introduces an approach that deals with non-linearities by detecting distinct sub-parts in the data. Sub-models each representin...
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ISBN:
(纸本)1901725294
Autonomous model building is a crucial trend in model based methods like AAMs. This paper introduces an approach that deals with non-linearities by detecting distinct sub-parts in the data. Sub-models each representing an individual sub-part are derived from a minimum description length criterion. Thereby the resulting clique of models is more compact and obtains a better generalization behavior than a single model. The proposed AAM clique generation deals with non-linearities in the data in a generic information theoretic manner reducing the necessity of user interaction during training.
Video watermarking plays an important role intoday's copyright protection of video media, in this paper a blind watermarking algorithm for mpeg2 video is proposed. In this algorithm, several DCT intermediate frequ...
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Video watermarking plays an important role intoday's copyright protection of video media, in this paper a blind watermarking algorithm for mpeg2 video is proposed. In this algorithm, several DCT intermediate frequency coefficients of the video pictures are selected and divided into some groups, the watermark was embedded into the video pictures by adjusting the intermediate frequency coefficients in each group. The watermark capacity of this algorithm is adequate and experimental result shows the proposed algorithm is robust to video compression attack within a certain range and has little effect on the quality of the video.
In this paper we describe modifications of irregular image segmentation pyramids based on user-interaction. We first build a hierarchy of segmentations by the minimum spanning tree based method, then regions from diff...
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At present, many chaos-based image encryption algorithms have proved to be unsafe, few encryption schemes permute the plain images as three-dimensional（3D） bit matrices, and thus bits cannot move to any position, th...
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At present, many chaos-based image encryption algorithms have proved to be unsafe, few encryption schemes permute the plain images as three-dimensional（3D） bit matrices, and thus bits cannot move to any position, the movement range of bits are limited, and based on them, in this paper we present a novel image encryption algorithm based on 3D Brownian motion and chaotic systems. The architecture of confusion and diffusion is adopted. Firstly, the plain image is converted into a 3D bit matrix and split into sub blocks. Secondly, block confusion based on 3D Brownian motion（BCB3DBM）is proposed to permute the position of the bits within the sub blocks, and the direction of particle movement is generated by logistic-tent system（LTS）. Furthermore, block confusion based on position sequence group（BCBPSG） is introduced, a four-order memristive chaotic system is utilized to give random chaotic sequences, and the chaotic sequences are sorted and a position sequence group is chosen based on the plain image, then the sub blocks are confused. The proposed confusion strategy can change the positions of the bits and modify their weights, and effectively improve the statistical performance of the algorithm. Finally, a pixel level confusion is employed to enhance the encryption effect. The initial values and parameters of chaotic systems are produced by the SHA 256 hash function of the plain image. Simulation results and security analyses illustrate that our algorithm has excellent encryption performance in terms of security and speed.
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