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The present study is conducted in two phases. In the first phase we analyze the different aspects of gray image watermarking in a colored host. Robustness and imperceptibility are used as analysis parameters. The approaches explored and compared in this study are — watermark embedding with any one of the three RGB (Red-Green-Blue) components (single channel embedding), multichannel watermark embedding...
Segmentation of myocardium in Late Gadolinium Enhanced (LGE) MR images is often difficult due to accumulation of contrast agent in the infarct areas, leading to poor delineation from adjacent blood pools. Thus, manual determination of the endo- and epicardial contours is challenging, time consuming, and subject to significant intra- and inter-observer variability. In this paper, we propose to use...
The random walker method [1] has many nice characteristics for 3D image segmentation. However, it is computational expensive and slow due to a massive linear system to be solved. In this work, we take advantage of the probabilistic output from the random walker method applied to a small downsampled image. By using the original image and seeds information, a novel edge-preserving method is introduced...
Center-surround measurements are widely used for saliency detection but with some disadvantages: 1) Center-surround operation may cause inaccurate segmentation and even involve incorrect detection results; 2) In most situations, only using center-surround feature is not efficient to encode object saliency. To overcome these disadvantages, we describe a novel measurement, namely Corner-Surround Contrast...
In order to enhance the adaptability of visual inspection systems to different environmental illuminations and backgrounds in projects, to eliminate the interference owing to various disturbances, such as the noises of inside circuits, the ideal model and the actual situation with the disturbances of noise of a gray transition region of a target edge was investigated and a new self-adaptive method...
This paper presents an approach of visual SLAM using line segments as primitives. We choose Pl ¨ucker lines to represent spatial lines and derive a novel fast line projection function based on the relationship between Pl¨ucker line and Pl ¨ucker matrix. During normal SLAM procedure, the Near by Line Tracking (NLT) method is adopted to track lines and an Extended Kalman Filter (EKF) is used to predict...
Parametric deformable models are an important technique for image segmentation. In order to improve the robustness of the model, it may be interesting to incorporate a priori information about the shape of the objects to be segmented. In this paper, we propose to add a parallelism constraint. Such a model is relevant in many applications where elongated structures have to be detected. One main advantage...
This paper proposes a method of extrinsically calibrating cameras in a rectangular room-like environment. It searches for line segments to indicate planar surfaces in the scene, mainly floor, walls and ceiling and uses the homographical relation between matching features on those surfaces to solve for the calibration parameters of the camera and the planes. It is assumed that the environment follows...
This paper presents a new method in a variational level set framework for ultrasound images segmentation. The conventional intensity gradient based methods have had limited success on ultrasound images. Phase based methods, which are theoretically intensity-invariant, offer a good alternative. The proposed approach uses a speed term based on local phase derived from the monogenic signal. In order...
This paper presents the mixed software-hardware conception approach. The software part was developed by the visual C++ language, and the hardware part was developed by the Handel-C language on FPGA circuit. We also present three methods of edges detection applicable for the real-time image segmentation and objects recognition: Prewitt, Sobel and Canny detectors. A comparison result is obtained between...
Conventional clinical diagnosis of tuberculosis disease such as manual screening by microbiologist are tedious, laborious and time consuming. Therefore, more research has been carried out to develop technologies that able to automate the detection process. This paper presents an automated approach to tuberculosis bacilli detection in tissue section. The proposed approach employs image processing technique...
Ensuring watermark invisibility in digital images is a challenging task. Most watermarking techniques empirically adjust a strength parameter in order to reach the best trade-off between invisibility and robustness. A target PSNR value is typically set in order to reach a defined quality level. Some watermarking techniques exploit local activity to increase the watermark strength in some specific...
We present a change detection method resistant to global and local illumination variations for use in visual surveillance scenarios. Approaches designed thus far for robustness to illumination change are generally based either on color normalization, texture (e.g. edges, rank order statistics, etc.), or illumination compensation. Normalization based methods sacrifice discriminability while texture...
Image matting is the process of extracting a soft segmentation of an object in an image as defined by the matting equation. Most current techniques focus largely on computing the alpha values of unknown pixels and treat computation of the foreground and background colors as an afterthought, if at all. However, for many applications, such as compositing an object into a new scene or deleting an object...
This article proposes a new method for robust and accurate detection of the orientation and the location of an object on low-contrast surfaces in an industrial context. To be more efficient and effective, our method employs only artificial vision. Therefore, productivity is increased since it avoids the use of additional mechanical devices to ensure the accuracy of the system. The technical core is...
Several pixel-based people counting methods have been developed over the years. Among these the product of scale-weighted pixel sums and a linear correlation coefficient is a popular people counting approach. However most approaches have paid little attention to resolving the true background and instead take all foreground pixels into account. With large crowds moving at varying speeds and with the...
A robust subpixel registration method for image mosaicing is presented in this paper. The method takes advantage of frequency-domain characterization to estimate the geometric transformation between images. The rotation and scale parameters between the to-be-mosaiced images are converted to translations by the Fourier-Mellin Transform (FMT), then the translation is estimated by the phase correlation...
This paper presents a novel non-rigid object localization and segmentation algorithm using an eigenspace representation. Previous approaches to eigenspace methods for object tracking use vectorized image regions as observations, whereas the proposed method uses each individual pixel as an observation. Localization using the pixel-wise eigenspace representation is robust to noise and occlusions. A...
Existing methods for the registration of blurred images are efficient for the artificially blurred images or a planar registration. They are not suitable for image mosaic of the source images from a real camera with an almost fixed optical center. We propose a registration method so that a distortion-free registration on naturally captured images can be obtained. It adopts a multi-resolution and robust...
Many schemes for digital watermarking have suffered tremendous frustrations on geometrical attacks. In this paper, a new method is proposed to try to solve the difficulties. The original watermark is embedded into a standard image which is acquired through translation and scaling normalization to the host image. The standard image is divided into small blocks. After singular value decomposition (SVD)...
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