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Contrast enhancement is one of the most studied problems in image processing. A plethora of approaches has been proposed in the literature for image enhancement since the pioneer work of Kovasznay and Joseph in 1955 [1] and the famous contribution of Gabor in 1965 on image deblurring [2]. However, very few works have been dedicated to contrast enhancement evaluation. This is mainly due to the fact...
In this paper, we present an unsharp masking-based approach for noise smoothing and edge enhancing. And apply it to color image processing. The proposed structure is similar to the conventional unsharp masking structure, however, a nonlinear function is added to control the behavior of the operator. The proposed scheme enhances the true details, limits the overshoot near sharp edges and attenuates...
In this paper, a Markov Random Field (MRF)-based method is presented. MRF methods are based on a probabilistic representation of a image processing problem; the problem is represented as the maximization of a probability measure computed starting from input data for all possible solutions. The optimization process is often computationally expensive. The coupled problem of restoring and extracting...
We propose a novel depth maps refinement algorithm and generate multi-view video sequences from two-view video sequences for modern autostereoscopic display. In order to generate realistic contents for virtual views, high-quality depth maps are very critical to the view synthesis results. We propose an iterative depth refinement approach of a joint error detection and correction algorithm to refine...
Edge detection is one of the most commonly used operations in the field of image processing. The traditional Canny edge detector is widely used in gray-scale image processing. However, this traditional edge detector is unable to deal with color images efficiently. The problem arises due to the double threshold technique: hysteresis threshold. In this paper, we have developed a new double threshold...
Image edge detection is one of the most important foundations of image analysis and comprehension. Traditional edge detectors are not robust enough to illumination variations. In last decade, detector based on Phase Congruency (PC) model was proposed and invariant to illumination variations. In this paper, we introduce the quaternion Wavelet Transform to PC model and propose a new edge metric of quaternion...
Depth maps provided by Microsoft Kinect often contain large dark holes around depth boundaries and occasional missing pixels in non-occluded regions, as well as noise, which prevent their further usage in real-world applications. In this paper, we present a graph Laplacian based framework to restore missing pixels based on the strong correlation between color image and depth map. To preserve sharp...
Depth maps generated by Kinect cameras often contain a significant amount of missing pixels and strong noise, limiting their usability in many computer vision applications. We present a new energy minimization method to fill the missing regions and remove noise in a depth map, by exploiting the strong correlation between color and depth values in local image neighborhoods. To preserve sharp edges...
This paper presents a new binarization method for color images of degraded historical document. The proposed method makes use of local image equalization based on color constancy, and an extension to the standard difference of Gaussians edge detection operator, XDoG. The binarization is achieved after three main steps: the first step removes undesirable degradation artifacts using a local image equalization...
This paper presents a cross-based framework of performing local multipoint filtering efficiently. We formulate the filtering process as a local multipoint regression problem, consisting of two main steps: 1) multipoint estimation, calculating the estimates for a set of points within a shape-adaptive local support, and 2) aggregation, fusing a number of multipoint estimates available for each point...
An adaptive marker extraction-based watershed algorithm is proposed to overcome the over-segmentation problem. By combining local minima depth and water basin scale information, markers are adaptively extracted for local minima, and the threshold for marker-extraction is automatically calculated according to the statistics of local extreme points in the gradient map. These markers are imposed on the...
In this paper a modified simple edge preserved denoising algorithm to remove salt and pepper noise in digital color images is presented. The algorithm has three steps: noisy pixel detection, replacement of noisy pixels, confirmation by comparing with a threshold. In additon a median filtering is added to improve the qualityof the image. The proposed algorithm prevents the smoothing of edges in the...
Microsoft's Kinect as a recent 3D sensor has attracted considerable research attention in the fields of computer vision and pattern recognition. But its depth image suffers from the problem of poor accuracy caused by invalid pixels, noise and unmatched edges. In this paper, an efficient approach is proposed to improve the quality of Kinect's depth image. Using its corresponding color image, the pixels...
Depth maps captured by Kinect-like cameras are lack of depth data in some areas and suffer from heavy noise. These defects have negative impacts on practical applications. In order to enhance the depth maps, this paper proposes a new inpainting algorithm that extends the original fast marching method (FMM) to reconstruct unknown regions. The extended FMM incorporates an aligned color image as the...
To the problem of the existing multi-scale edge detection methods couldn't tackle de-noising and edge detail preservation of images, the article proposed a multi-scale edge detection algorithm which took soft threshold method to implement detail enhancement and noise reduction of the true color image. Firstly, obtaining the true color images at different scales through wavelet multi-scale edge detection...
Image enhancement is used to improve quality of images for further analysis. In this paper, we proposed a color image enhancement method with the use of sparse representation of orthogonal transform based on the characteristics of discrete cosine transform (DCT) coefficients: fewer nonzero coefficients exist in smooth domains, the amplitudes of DCT change slightly in texture contents but significantly...
The automatic face tracking and detection has been one of the fastest developing areas due to its wide range of application, security and surveillance application in particular. It has been one of the most interest subjects, which suppose but yet to be wholly explored in various research areas due to various distinctive factors: varying ethnic groups, sizes, orientations, poses, occlusions and lighting...
In this paper we propose a fast and robust descriptor for multiple view object recognition using a small number of training examples. In order to design a descriptor to be discriminative between many different object appearances, we base it on a combination of invariant color, edge and texture descriptors. We use a color descriptor based on a HSV histogram - as it is robust to size and position of...
A novel edge detection technique for color images is presented in this paper. In the proposed method, contemporary fuzzy logic is used to implement a relative pixel similarity value algorithm. The smoothness of each pixel is calculated in four directions by use of weighted similarity rules and is normalized to maximum gray level. In other words, image in three dimensional color spaces is mapped into...
A novel technique is presented to detect and remove the salt and pepper noise in digital color images. The algorithm is proposed for detection of noisy pixel, edges and noise free pixels by utilizing basic property of salt and pepper noise. Each pixel is treated according whether it is edge pixel, noisy pixel or pixel from smooth region etc. Noisy pixel are replaced with median of neighborhood of...
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