edge-preserving filters

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Descreening the Scanned Halftone Image using Adaptive and Edge Preserving Filters

Descreening the Scanned Halftone Image using Adaptive and Edge Preserving Filters

Abstract-- Electro photographic printers utilizes half toning method to print persistent tone pictures, so scanned pictures acquired from such hard duplicates are generally ruined by screen like antiquities. Another model for recuperating filtered halftone shading picture is actualized. This new approach considers both printing distortions and halftone designs. Twists are evacuated by method for a versatile sifting system. At first BM3D calculation is proposed in which Collaborative separating is an exceptional technique, created to manage these 3D gatherings. This BM3D is in light of this novel denoising methodology. Next gimmick extraction methodology is proposed, for example, Screen Frequency Estimation and Local Gradient Extraction. Next Adaptive Filtering Algorithm is utilized for separating the scanned picture with obliged limit esteem. At that point Edge-Preserving Algorithm has been proposed to protect the edge of the checked picture. Here NLM calculation is utilized for Edge- Preserving. Non-neighborhood means is a calculation for picture denoising which takes the mean estimation of a gathering of pixels encompassing a target pixel to smooth the picture. At last the Descreened examined shading pictures with ceaseless tones are acquired.
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A Study on Image Enhancement and Resolution through fused approach of Guided Filter and high resolution Filter

A Study on Image Enhancement and Resolution through fused approach of Guided Filter and high resolution Filter

Abstract: In this paper we will present approach or technique for the “Guided Image Filtering and High Resolution filtering”. A lot of methods are available for Guided Image Filtering like Edge preserving Filtering, Gradient Preserving Filtering, Extension to color filtering, Structured Transferring Filtering, Median Filtering, Bilateral Filtering etc. The guided filter can perform edge-preserving smoothing operator like the popular bilateral filter. The guided filter generates the filtering output having the content of a guidance image which can be the input image itself or another different image. The guided filter has a fast and non-approximate linear-time algorithm whose computational complexity is independent of the filtering kernel size. This method shows outstanding performance in terms of classification accuracy and computational efficiency. Edge-preserving image smoothing has valuable tool for a variety of application such as denoising, tone mapping, non-photorealistic rendering in computer graphics and image processing. Edge-Preserving filters and guided image filtering algorithms are based in terms of quality measurement parameters like PSNR and SSIM.
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Novel Object-Based Filter for Improving Land-Cover Classification of Aerial Imagery with Very High Spatial Resolution

Novel Object-Based Filter for Improving Land-Cover Classification of Aerial Imagery with Very High Spatial Resolution

Image filters, especially the edge-preserving filter, have recently been proposed to smooth noise in images with a high spatial resolution and improve land cover classification accuracy. Edge-preserving filters have been adopted in many applications [23–25]. For example, Kang et al., proposed a spectral–spatial classification framework based on an edge-preserving filter and obtained a significantly improved classification accuracy [26]. They also presented a recursive filter combined with image fusion to enhance image classification [27]. Xia et al., proposed a method that combines subspace independent component analysis and a rolling guidance filter for the classification of hyperspectral images with high spatial resolution [28]. Experimental results showed that the proposed method gives a better accuracy than the traditional approach without the use of image filtering. From the application viewpoint, these simple yet effective approaches imply the many potential applications of VHSR images.
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Removal of Artifacts Based on Weighted Guided Filtering For Digital Video Quality Enhancement

Removal of Artifacts Based on Weighted Guided Filtering For Digital Video Quality Enhancement

It is known that local filtering-based edge preserving smoothing techniques suffer from halo artifacts. Local filter cannot preserve sharp edges when compared to global filters. Such that, halo artifacts are usually produced when local filters adopt to smooth edges.In this paper, weighted guided image filter (WGIF) is proposed by incorporating an edge-aware weighting into an existing guided image filter (GIF) to address the problem. The WGIF is used to adopts both the advantages of global and local smoothing filters in the sense that: 1) the complexity of the WGIF is O(N) for an image with N pixels, which is same as the GIF and 2) the WGIF can avoid halo artifacts like the existing global smoothing filters. The WGIF is applied for single image detail enhancement, single image haze removal, and fusion of differently exposed images. Experimental results shows that the resultant image produces better visual quality by reducing/avoiding the halo artifacts to zero. The extension work is performed on videos, where this video consists of no. of frames. Each frame is converted into image. Every image is filtered by WGIF technique to avoid halo artifacts and to reduce the complexity. After then each image is again converted into frame and then video. The improved quality of video is shown in below results. KEYWORDS: Edge-preserving smoothing, weighted guided image filter, edge aware weighting, detail enhancement, haze removal.
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Despeckling of Optical Coherence Tomography Images: A Comparative Study

Despeckling of Optical Coherence Tomography Images: A Comparative Study

Fig.1 gives statistics of the denoising filters that were executed. Fig.2 and Fig.3 are original and noisy images respectively. The outputs obtained from the execution of various denoising filters are listed from fig.4 to fig.13. The result shows that bilateral filter has a higher PSNR value, lower RMSE values compared to other filters. The UQI and SSIN values of the bilateral filter show that the quality and the structural similarity of the denoised image are improved. The correlation coefficient value of the bilateral filter indicates that there is less correlation between original image and denoised image. The ENL value of the bilateral filter shows that there are more uniform region in the denoised image, but the deflection ratio of the filter indicates that the reflection points of the denoised image is very low.
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Privacy Preserving Personalized Data by Sobel Edge Detection in Hybrid Cloud

Privacy Preserving Personalized Data by Sobel Edge Detection in Hybrid Cloud

We give a specific realization based onthe techniques of Sobel edge detector, tent-logistic system andcompressed sampling. An image is first distinguished to obtainsensitive data set and insensitive data set with the help of Sobeledge detector. Then, the sensitive dataare encrypted in parallelin the similar way of the counter mode. The insensitive data areencrypted with the architecture of permutation-diffusion andare then subsampled by parallel compressed sampling technique.The encrypted sensitive data are stored in the privatecloud while the compressed measurements of the insensitive data are outsourced to the public cloud for storage. Such anoutsourcing means the private cloud saves abundant storagespace through outsourcing the greater than 80% data of animage to the public cloud.
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DE-NOISING RADIOGRAPHIC IMAGES USING BILATERAL EDGE PRESERVING FILTER

DE-NOISING RADIOGRAPHIC IMAGES USING BILATERAL EDGE PRESERVING FILTER

Competition among industries, quality of equipment and materials becomes basic requirement to remain competitive across markets. Non-destructive is one of the oldest techniques, even though radiography is obeying as control of weld joints in many industries such as chemical, nuclear, naval, aeronautical industries. For critical applications it plays a important role. Where weld failures breakdown occur. Such as in pressure vessels, power plant and load- bearing. Knowledge of welded joint features and types of defects can be detected can be detected in radiographic welded joint inspection in necessary. However, global economic development has gradually led steal production industries increases it production rate on the quality of product. In order to increase production for high quality in short duration, the use of visual inspection systems increase its production lines. The use of visual inspection systems increases its production lines and automated inspection technique is necessary to improve quality of product as well as to eliminate the need of human intervention in hazardous environment. It has An improved radiographic image denoising using bilateral filtering and edge preserving by snake method. In digital radiographic input image contain noise and denoise by using bilateral filter. It is a non-linear, and noise reduction smoothening filter. Intensity value at each image pixel is replaced by average of intensity values from nearby pixels. For detecting edges in radiographic images, discontinuous contours can be obtained in traditional approach, due to attenuation of sound wave and speckle noise. Developing snake edge detection.
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AN EDGE PRESERVING MULTIRESOLUTION FUSION USING CURVELET TRANSFORM AND MRF PRIOR

AN EDGE PRESERVING MULTIRESOLUTION FUSION USING CURVELET TRANSFORM AND MRF PRIOR

This project presents a new technique for multiresolution image fusion using curvelet- based learning and MRF prior. In the proposed method, we first obtain the initial high- resolution MS image by the available Pan image and the test MS image. Since the initial estimate has high spatial and spectral resolutions, it is used to obtain the degradation between fused MS and test MS image, where the blur is assumed to be a nonidentity matrix. We cast the fusion problem in the restoration framework and obtain the final solution by using the regularization framework. The final cost function is obtained using the MAP-MRF approach, where MRF smoothness prior is used to regularize the solution. The edge details in the final fused image are obtained by applying Canny edge detector on the initial estimate. The MRF parameter is also estimated using the initial estimate image, which is used during optimization. Experimental results demonstrate that the proposed method recovers the finer details with minimum spectral distortion. In addition, the perceptual and the quantitative analysis show that the proposed technique yields better solution when compared with the state-of-the-art approaches.
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Restoring degraded images and edge detection using optimal adaptive thresholding and filters

Restoring degraded images and edge detection using optimal adaptive thresholding and filters

Detectors based on optimality criteria are often derived in continuous one dimensional domain and are extended to two dimensional domains in a subjective way that lacks firm logical justification. Also, a problem very commonly faced by detectors is the choice of threshold values, which are often chosen on heuristic basis. Prewitt’s, Roberts’, and Sobel’s operators and zero-crossing edge detectors use thresholds which are generally selected without any precise objective guideline. In the Mat lab, version of Canny’s edge detector the most popular among all edge detectors thedefault value of upper threshold is suggested to be 75th percentile of the gradient strength. In order to automatically find a threshold, standardization of gradient magnitudes is to be done relative to the surrounding pixels’ gradient magnitudes, and, then, it is to be tested whether the obtained value is large or not. A natural way of doing such standardization in any procedure is to use appropriate statistical principles. A way of accomplishing the above objective is obtained by the method proposed (Rishi et al., 2004) in this work. This method of standardizing the gradient strength at each pixel locally before thresholding results in the removal of the ambiguity and inap- propriateness in choosing global threshold values, and thereby produces reliable, robust, and smooth edges. Local image statistics have been used earlier by Chow and Kaneko (Chow and Kaneko, 1972) to get boundaries in images, and their algorithm was modified by Peli and Lahav (Peli and Lahav, 1986) for the purpose of detecting bright objects in darker backgrounds. Suppose that an image contains only two principal gray-level regions. Let z denote gray-level values. The values are Article History:
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A Post Processing Algorithm for Spatial Domain Detection & Removal of Blocking Artifacts

A Post Processing Algorithm for Spatial Domain Detection & Removal of Blocking Artifacts

Over the past several years, large number of de-blocking algorithm for post-processing approach to remove blocking artifacts, have been proposed. The most common method is applying LPF over the block boundaries. For Blocking artifacts, low-pass filters can accomplish great execution by using various processes but the disadvantages of the spatial filtering methodology are smoothing or over smoothing of pictures because of its low-pass property. Various strategies have been proposed to mitigate blocking artifacts in the DCT area. Low-pass filtering smoothens out the high-frequency parts close to the limits of DCT blocks. Be that as it may, low-pass filtering brings about the accessible information on the first un-coded picture. Iterative calculations of POCS (projections onto these convex sets) recuperate the original picture from the coded one. But these techniques for the most part have high computational multifaceted nature and subsequently are hard to adjust to continuous/real time picture handling applications. Luo et al. proposed a simple DCT-based de-blocking method for smooth regions [5].In this technique, due to use of LPF high frequency signals are not considered while uneven regions are not regulated . Human eyes are more sensitive to low frequency signals than to high frequency signals. As this method was not much workable on blocking artifacts, it resulted in poor performance across the output images[6-7]. In [8] signal disintegration based strategy was proposed and its advanced technique was explained in [9]. This technique was caused by over blurring due to separation in DCT domain, particularly in comprehensive regions.[10-11]. Also, these are all more unpredictable strategies than spatial sifting. Iterative post processing methodologies were at first proposed by Youla and Webb [12,13
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Privacy-preserving Record Linkage

Privacy-preserving Record Linkage

The results of a small simulation of PPRL using two files with 10,000 records is shown in figure 10. Larger step sizes decrease the performance (at least for the given window size here). Larger number of hash functions increase performance for re-hashing. For the parameter settings used here (no additional errors, overlap of 100%), lower similarity thresholds show better results for all but one experiment. The lower right figure (s = 8) demonstrates a decrease in linkage quality below a similarity threshold of .75. Below this threshold, the number of false positives increases sharply; therefore the precision and accordingly the F-Score becomes unacceptable. However, high values of precision and recall can be achieved with small (5 < s < 10) step sizes, high numbers of hash functions (k ≥ 12) and moderate similarity thresholds (0.75 ≤ t ≤ 0.8). Therefore, the idea of re-hashing CLKs or other Bloom filters seems to deserve further study. Since the choice of these parameters depend on m and k and the number of q-grams per identifier, the choice of optimal parameters for re-hashing is subject to ongoing research.
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Infrared stripe correction algorithm based on wavelet decomposition and total variation-guided filtering

Infrared stripe correction algorithm based on wavelet decomposition and total variation-guided filtering

The purpose of our research is to propose a single- frame image processing algorithm, which can achieve stripe non-uniformity correction from the first frame without losing the edge information. The proposed algo- rithm mainly consists of three parts. Firstly, the image processing algorithm based on wavelet decomposition extracts the high-frequency components of the image, and decomposes the high-frequency components into vertical components, horizontal components and diag- onal components. At the same time, the original image is smoothed by small-scale using the total variation algo- rithm. The small scale total variation algorithm can keep the edge information of the image well, but it will leave stripe noise. Since stripe noise is caused by the fact that each column of infrared detector readout circuit shares the same amplifier, and the non-uniformity between am- plifiers leads to the formation of fixed stripe noise in the image, according to prior knowledge, stripe noise mainly exists in the vertical component [1]. In the spatial filter- ing step: the vertical component is taken as an input image, and the smoothed image is used as a guide image for stripe noise denoising. It can prevent the strong stripe noise from being mistaken for the edge detail by the guided filter and lead to the residual stripe noise in the corrected image. The proposed algorithm can elim- inate the stripe noise directly in the component part and simultaneously retaining image details.
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To Mask or Not to Mask? Balancing Privacy with Visual Confirmation Utility in Activity-Oriented Wearable Cameras | KA MOAMOA

To Mask or Not to Mask? Balancing Privacy with Visual Confirmation Utility in Activity-Oriented Wearable Cameras | KA MOAMOA

3.10.1 Statistical Analysis: RQ1 - Visual Confirmation Utility. We first calculated the proportion of correct responses to A.Q3, "What is Person A doing (with their right hand)?", from the as-is (no obfuscation), blur, blurH, edge, edgeH, and mask arms. Since we do not obfuscate the hand-related activities, we hypothesized that each of the five obfuscation arms would be equivalent (or noninferior) to the as-is arm in correctly identifying the activity of the wearer. To test the relative preservation of visual confirmation utility, we used a two one- sided equivalence test [39, 65, 77], a variant of classic null hypothesis testing. Here, the null hypothesis was that the as-is proportion of correct responses (p a ) would be superior to the proportion of correct responses in an obfuscation arm (p o ) by at least a margin of (δ) percent (i.e., |p a − p o | ≥ δ). The margin represents the tolerability of the noninferiority test. The alternative hypothesis was that the two proportions were equivalent up to the tolerance margin (i.e., |p a − p o | < δ). In our main analysis, we specified our tolerance margin to be δ = 30% and later performed exploratory sensitivity analyses where we decreased the tolerance to 15% and 20%. Equivalence tests were performed using Python statsmodels package (0.9.0)[66] .
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A Study and Analysis of Bone Fracture Detection Methods A. Hemavathy 1, S. Agnes Shifani2 , G. Ramkumar 3

A Study and Analysis of Bone Fracture Detection Methods A. Hemavathy 1, S. Agnes Shifani2 , G. Ramkumar 3

Image processing is famous in modern data storage and data transmission especially in progressive transmission of images, video coding (teleconferencing), digital libraries, image database, and remote sensing. Nowadays image processing is widely used in medical image processing which comprises medical image enhancement and visualization, and edge detection. One of its major applications is fracture detection using X-ray images. Fracture in bone occurs when an external force exercised upon the bone is more than what the bone can tolerate or bear. The fracture can occur in any bone of our body like wrist, heel, ankle, hip, rib, leg, chest etc. In this paper we discuss about the types of bone fracture that commonly occur, types of filters we can remove the noise from degraded image and the edge function is used to detect edges, which are those places in an image that correspond to object boundaries.
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‘Living on the edge’: using cognitive filters to appraise experience of environmental risk

‘Living on the edge’: using cognitive filters to appraise experience of environmental risk

Experience appraisal, cognitive appraisal, climate change, environmental risk, farmers 33 .. 34 .[r]

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IJCSMC, Vol. 2, Issue. 7, July 2013, pg.322 – 326 RESEARCH ARTICLE

IJCSMC, Vol. 2, Issue. 7, July 2013, pg.322 – 326 RESEARCH ARTICLE

The bilateral filter is nonlinear filters that smooth a signal while preserving strong edges. It has demonstrated great effectiveness for a variety of problems in computer vision and computer graphics, and a fast version has been proposed. This signal-processing perspective allows developing a novel bilateral filtering acceleration using a down sampling in space and intensity. This affords a principled expression of the accuracy in terms of bandwidth and sampling. The key to the analysis is to express the filter in a higher-dimensional space where the signal intensity is added to the original domain dimensions. The bilateral filter can then be expressed as simple linear convolutions in this augmented space followed by two simple nonlinearities.
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Profile Reconstruction Utilizing Forward-Backward Time-Stepping with the Integration of Automated Edge-Preserving Regularization Technique for Object Detection Applications

Profile Reconstruction Utilizing Forward-Backward Time-Stepping with the Integration of Automated Edge-Preserving Regularization Technique for Object Detection Applications

Abstract—A regularization is integrated with Forward-Backward Time-Stepping (FBTS) method which is formulated in time-domain utilizing Finite-Difference Time-Domain (FDTD) method to solve the nonlinear and ill-posed problem arisen in the microwave inverse scattering problem. FBTS method based on a Polak-Ribi` ete-Polyak conjugate gradient method is easily trapped in the local minima. Thus, we extend our work with the integration of edge-preserving regularization technique due to its ability to smooth and preserve the edges containing important information for reconstructing the dielectric profiles of the targeted object. In this paper, we propose a deterministic relaxation with Mean Square Error algorithm known as DrMSE in FBTS and integrate it with the automated edge-preserving regularization technique. Numerical simulations are carried out and prove that the reconstructed results are more accurate by calculating the edge-preserving parameter automatically.
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Edge Preserved and Segmented Image Denoising

Edge Preserved and Segmented Image Denoising

In this work, edge based segmentation is opted in which all pixels categorized based on edge labeling. An edge detection filter can perform the edge labeling automatically. Among these, Mean shift segmentation is the best player. This versatile method based on clustering can be simply defined as for each pixel choose a search window, then compute the mean shift vector and repeat till it converges.

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Effective Image Restorations Using a Novel Spatial Adaptive Prior

Effective Image Restorations Using a Novel Spatial Adaptive Prior

Copyright © 2010 Yang Chen et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Bayesian or Maximum a posteriori (MAP) approaches can effectively overcome the ill-posed problems of image restoration or deconvolution through incorporating a priori image information. Many restoration methods, such as nonquadratic prior Bayesian restoration and total variation regularization, have been proposed with edge-preserving and noise-removing properties. However, these methods are often inefficient in restoring continuous variation region and suppressing block artifacts. To handle this, this paper proposes a Bayesian restoration approach with a novel spatial adaptive (SA) prior. Through selectively and adaptively incorporating the nonlocal image information into the SA prior model, the proposed method effectively suppress the negative disturbance from irrelevant neighbor pixels, and utilizes the positive regularization from the relevant ones. A two- step restoration algorithm for the proposed approach is also given. Comparative experimentation and analysis demonstrate that, bearing high-quality edge-preserving and noise-removing properties, the proposed restoration also has good deblocking property.
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Experimental Study on Despeckling of PolSAR I...

Experimental Study on Despeckling of PolSAR I...

These techniques have different criteria of Despeckling the image where co variance matrix is used in Wis hart distribution and block matching is used in BM3D. Most of the techniques are filtering techniques i.e. Boxcar filter is simple as compared to other filters to apply and effective in suppression of speckle in homogeneous regions but it degrades the spatial resolution and blurs the target. The most important thing that is considered now is PSNR (power to signal noise ratio) and equivalent no. of looks (ENL). Both the quantities should be as high as possible if these values are high then speckle will be less or can say the image produced will be more efficient. In order to describe the estimation methods that have been developed for the Despeckling problem, we need firstly to introduce models for speckle, SAR system and reflectivity.
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