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In this paper, we present an efficient image interpolation scheme by using regularized local linear regression (RLLR). On one hand, we introduce a robust estimator of local image structure based on moving least squares, which can efficiently handle the statistical outliers compared with ordinary least squares based methods. On the other hand, motivated by recent progress on manifold based semi-supervise...
Graphical passwords are an authentication method that uses pictures as passwords instead of using alphanumeric characters. We propose a graphical password method which is difficult to steal original pass-image by using characteristics of human vision system. In our method, we combine low frequency components of a decoy picture with high frequency components of a pass-image. It is easy for legitimate...
This study develops a vision-based displacement measurement system for remote monitoring of vibration of large-size structures such as bridges and buildings. The system consists of one or multiple video cameras and a notebook computer. With a telescopic lens, the camera placed at a stationary point away from a structure captures images of an object on the structure. The structural displacement is...
This paper presents a robust motion detection technique using unit gradient vectors (UGVs). UGVs carry only gradient orientation information that is remarkably invariant to changes of image intensities. Hence, UGVs can be used as a stable textural feature in place of conventional image features intensities and gradients. We propose to detect motions in image sequences using the pixel-wise variations...
A semi fragile watermarking scheme for remote sensing images is presented. The suggested scheme uses the signature of the multispectral or hyper spectral image to embed the mark and detects a forgery of the marked image, e.g. a tampered region. The original image is segmented in three-dimensional blocks and, for each block, a discrete Wavelet transform (DWT) and a tree structured vector quantizer...
2D barcode recognition technique and system play an important role in the industry application. It is extremely challenging to locate and recognize barcodes when the background is cluttered and the illumination is uneven. In this paper, we propose a hierarchical framework for 2D Data Matrix recognition and further introduce the 2D barcode recognition system based on the proposed method. The superiority...
In the field of nanotechnology, tracking freely swimming microorganisms under a microscope is difficult. An image of the target often rotates and changes shape as it moves. Further, the difficulty increases with background changes and fluctuations of colors and the brightness because of differences in the surrounding environment. To address these problems, we propose a tracking method combined with...
Image stitching are ideally suited for applications such as image stabilization, summarization, and the creation of panoramic mosaics. This paper proposes a approach to stitch images fast and with high quality.Image alignment algorithms can discover the correspondence relationships among images with varying degrees of overlap. In this process, they uses SIFT to look for the trait points, and uses...
Document image distortion often appears when captured by the camera; this may induce recognition mistakes by OCR. In this paper, a robust and fast dewarping method of document images is proposed. Compared with traditional method, the computation of the correction baseline and the distance for vertical displace in this method is independent of the document's content, so it can guarantee the precision...
We are focused on how to describe a common image point distinctively, make its descriptor concise and invariant to general image transformations. We use neighborhood pixel characteristics, including HSV color space, Gaussian-weighted gradient magnitudes and orientations, sampled in specific window around interest point to enhance the description. The enhanced point descriptor (EPD) is a covariance...
Crowd density analysis is crucial for crowd monitoring and management. This paper proposes a novel method for crowd density analysis. According to the framework, input images are firstly divided into patches, and each patch is associated with a density label based on its texture features. Finally, local information is synthesized for global density estimation. Local image content is described by features...
We present an approach to global image registration that allows a robust and efficient image alignment, required in various mobile imaging applications (e.g. multi-frame image enhancement, high dynamic range imaging, panoramic image stitching). The proposed method follows a coarse to fine strategy, adopting different registration techniques at coarse and fine resolution levels. Coarse levels are registered...
It has been shown that the probability to develop breast cancer is strongly correlated with the appearance of tissue in mammographic images. This appearance incorporates both greylevel and tissue pattern aspects and models of local texture information, which incorporate both greylevel and spatial aspects, can as such be related to mammographic risk assessment. Here we represent texture by the variation...
The fuzzy c-means (FCM) algorithm has been applied in a variety of medical image segmentation applications. The conventional FCM algorithm uses the greylevel information at a single pixel as the feature space and this contains no spatial contextual information, which makes it very sensitive to noise and intensity inhomogeneities. Recently, some modified FCM algorithms with spatial constraints have...
We present a novel blind digital watermarking algorithm using the quantization for Jaguwen rubbing image based on Contourlet transform in this paper. After Contourlet transform, original image is decomposed into a series of multiscale, local and directional subimages. Select the low frequency subband as the watermarking embedding domain. At the same time, the original binary watermark is firstly scrambled...
In this work, we present a novel local pattern descriptor, Local Gradient Derivative Pattern (LGDP) to face recognition which considers more detailed information than the Local Binary Pattern (LBP). The face image is first divided into several small regions from which Local Gradient Derivative Pattern (LGDP) histograms are extracted and concatenated into a single, spatially enhanced feature vector...
We present a method for foreground-background video segmentation in real-time that may be used in applications as, for instance, Background Substitution, Analysis of Surveillance Cameras, Highway Cars Detection and so on. Our approach implements a probabilistic segmentation based on the binary Quadratic Markov Measure Fields models (QMMFs). That framework regularizes the likelihood of each pixel to...
The performance evaluation of watermarking scheme is done by two performance metrics: perceptual transparency and robustness. Perceptual transparency refers quality of image which is measured by `Peak Signal to Noise Ratio' (PSNR). Robustness is measured in terms of `Correlation Factor' (ρ). A good quality watermarking scheme should have maximum PSNR, ideally Correlation Factor equals to...
Acquisition of consistent multi-camera image data such as for time-slice sequences (widely known by their use as cinematic effects, e.g. in “The Matrix”) is a challenging task, especially when using low-cost image sensors. Many different steps such as camera calibration and color conformation are involved, each of which poses individual problems. We have developed a complete and extendable setup for...
The problem of image registration is to find the best set of parameters of an affine transformation, which applied to a given image yields the closest match to a target image (possibly with noise). We present a method to perform parametric image registration based on Differential Evolution. Besides using Differential Evolution, we propose to use an error function robust enough to discard misleading...
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