The LLP-distance was first introduced for use in clustering problems by Fischer et. al. , creating the field of path-based clustering. The LLP-distance is used to define a clustering cost function which is then minimized by an Iterated Conditional Mode algorithm using multi-scale techniques to improve computational performance. This algorithm was shown to outperform other concurrent top agglomeration methods on artificial data sets as well as segmentation of textured images. This algorithmic framework was later modified to include automatic outlier detection by inclusion of an outlier class, which was shown to perform well for edgel grouping and textured data . In a later publication, Fischer et. al. proved that the LLP-distance is an ultrametric and thus the matrix of LLP-distances was shown to induce a Mercer’s Kernel . This allows for an approximation of the path-based clustering result by applying k-means clustering to a lower dimensional embedding of path-based distances using Kernel Principle Components Analysis. This technique has the advantage of de-noising the hierarchy created by their previous agglomerative method, leading to a more robust method. This also lead the way for path-based spectral clustering.
To generate candidate regions, several methods have been applied in the current research studies: (1) one of the ideas relies on threshold segmentation for different color channels. Similarly, Duan et al. applied an algo- rithm to extract potted rice panicles from multi-angle side-view images . The hysteresis thresholding based on the i2 color plane is applied to extract the panicle can- didate regions. Obviously, imagesegmentation of pani- cles in pot-grown rice, which is inspected in a chamber with a stable illumination environment, is relatively sim- ple compared with phenotyping in field environments. (2) Another thought for candidate regions generation is utilizing a classifier, such as the support vector machine (SVM). The gray values for different color spaces, such as the RGB, HSV and LAB color planes, are calculated as the input vector of the SVM classifier. For example, Zhu et al. introduced a wheat ear detection mechanism to automatically observe the wheat heading stage . The proposed method is applied to generate wheat ear can- didate regions with SVM. In addition, Lu et al. developed a framework called mTASSEL-S to execute the maize tassel segmentation . The color space conversion is used to make a coarse location easier with SVM. (3) Fur- thermore, there is the consideration that the candidate regions could rely on graph-basedsegmentation. Simi- larly, Lu et al. in 2016 proposed a method for maize tassel segmentationbased on region-based color modeling .
We have presented a combined unsupervised imagesegmentation and denoising frame- work that is basically the first derivative Potts model and based on the piecewise constant assumption. We formulate it into a MILP and add the 4-edge cycle multicut constraints to cut off feasible but non-optimal solutions. We then apply it for superpixel generation, where each rectangular patch of the original image needs to solve a MILP. We conduct extensive experiments on BSDS500 image dataset with noises. Even without parame- ter training, our method achieves the best performance against 4 other state-of-the-art superpixel algorithms with optimized parameters on the combined OP score.
The increasing popularity of the internet suggests that digital multimedia has become easier to transmit and acquire more rapidly. This also means that this multimedia has become more susceptible to tampering through forgery. One type of forgery, known as copy-move duplication, is a specified type that usually involves image tampering. In this study, a keypoint-basedimage forensics approach based on a superpixelsegmentation algorithm and Helmert transformation has been proposed. The purpose of this approach is to detect copy-move forgery images and to obtain forensic information. The procedure of the proposed approach consists of the following phases. First, we extract the keypoints and their descriptors by using a scale-invariant feature transform (SIFT) algorithm. Then, based on the descriptor, matching pairs will be obtained by calculating the similarity between keypoints. Next, we will group these matching pairs based on spatial distance and geometric constraints via Helmert transformation to obtain the coarse forgery regions. Then, we refine these coarse forgery regions and remove mistakes or isolated areas. Finally, the forgery regions can be localized more precisely. Our proposed approach is a more robust solution for scaling, rotation, and compression forgeries. The experimental results obtained from testing different datasets demonstrate that the proposed method can obtain impressive precision/ recall rates in comparison to state-of-the-art methods.
Nobuyuki otsu  has proposed a nonparametric and unsupervised method of automatic threshold selection for picture segmentation is presented. An optimal threshold is selected by the discriminant criterion, namely, so as to maximize the separability of the resultant classes in gray levels. Qingyong Li  has proposed thin cloud detection for all-sky images is a challenge in ground-based sky-imaging systems because of low contrast and vague boundaries between cloud and sky regions. . In this model, each pixel is represented by a combined-feature vector that aims at improving the disparity between thin cloud and sky. The distribution of each label in the feature space is defined as a Gaussian model. J. Yang et al  has proposed an automatic cloud detection algorithm, “green channel background subtraction adaptive threshold” (GB SAT), which incorporates channel selection, background simulation, computation of solar mask and cloud mask, subtraction, adaptive threshold, and binarization. Several experimental cases show that the GBSAT algorithm is robust for all types of test total sky images and has more complete and accurate retrievals of visual effects than those found through traditional methods. Sylvio Luiz  has describes the use of multidimensional Euclidean geometric distance (EGD) and Bayesian methods to characterize and classify the sky and cloud patterns present in image pixels. From specific images and using visualization tools, it was noticed that sky and cloud patterns occupy a typical locus on the red–green–blue (RGB) color space. Genkova  has takes the effort to resolve uncertainties about global climate change, the Atmospheric Radiation Measurement (ARM) Program (www.arm.gov) is improving the treatment of cloud radiative forcing and feedbacks in general circulation models. Understanding cloud properties and how to predict them is critical because cloud properties may very well change as climate changes. The amount of clouds and cloud spatial and vertical distribution at any given time are required input parameter for improving the performance of general circulation models.
Hyperspectral images (HSIs) are often corrupted by noise during the acquisition pro- cess, thus degrading the HSI’s discriminative capability significantly. Therefore, HSI denoising becomes an essential preprocess step before application. This paper propos- es a new HSI denoising approach connecting Partial Sum of Singular Values (PSSV) and superpixelsegmentation named as SS-PSSV, which can remove the noise effec- tively. Based on the fact that there is a correlation between different bands of the same signal, it is easy to know the property of low rank. To this end, PSSV is utilized, and in order to better tap the low-rank attribute of samples, we introduce the superpixelsegmentation method, which allows samples of the same type to be grouped in the same sub-block as much as possible. Extensive experiments display that the proposed algorithm outperforms the state-of-the-art.
Many researchers have taken FCM algorithm as the starting point and modify it to solve the first shortcom- ing. In , a spatial function is introduced into the membership function; this spatial function is the sum- mation of the membership function in the neighbor- hood of each pixel under consideration. Ahmed et al.  modified the objective function of the FCM by add- ing a regularizer which considers the labels of all the neighboring voxels in an image to compensate the bias field effect of the data. Other authors such as Zhang and Chen  follow the same work of Ahmed et al. but their algorithms introduced the median- and mean- fil- tered images, which can be computed in advance and hence, can reduce the computation time. Zhao et al.  used an adaptive spatial parameter for each pixel that was designed to make the non-local spatial information of each pixel playing a different role to guide the noisy imagesegmentation. Liu and Pham  modified the
For block-based algorithms, an image is tessellated into a number of blocks followed by noise variance computa- tion in a set of homogeneous blocks [5, 17, 19]. The phil- osophy underlying this approach is that a homogeneous block in an image is treated as a perfectly smooth image block with added noise, which has a relatively higher chance to contain useful visual activities. Consequently, the block with a smaller standard deviation has a weaker variation in intensity, leading to a smoother block. One main difficulty of block-based approaches is how to effi- ciently identify the homogeneous blocks. Lee and Hoppel  estimated noise level by assuming that the smallest standard deviation of a block is equivalent to additive white Gaussian noise. This method is simple but tends to produce overestimation results for small noise cases. Shin et al.  split an image into a number of blocks, which were further classified by the standard deviation in inten- sity. An adaptive Gaussian filtering process was then applied to relatively flat blocks, where the noise was esti- mated from the difference of the selected blocks between the noisy image and its filtered image.
Abstract: Digital image processing has become important in the areas of communication, medicine, remote-sensing, seismology, industrial automation, robotics, aerospace and education. Imagedenoising is the technique used to remove the noisy components from the image and also to preserve the information carrying components. Noise can be introduced in the image for various reasons as well as in different steps in image processing like image acquisition or image compression. Wavelet transform method using Neigh SURE (Stein’s Unbiased Risk Estimator) thresholding is applied for imagedenoising because of some distinct advantages offered by the technique like its quantization property. This method will be implemented on LabVIEW. In this method first wavelet transform decomposition is obtained over noisy image to get sub divided components then by thresholding the coefficient is adjust according to thresholding and filter out unwanted noise components. Then by applying inverse wavelet transform the denoised image is reconstructed called derived image. By means of PSNR (Peak Signal to Noise Ratio) and MSE (Mean Square Error) algorithm calculates the performance, quality and accuracy of the resultant image. Keywords— Wavelet Algorithm, Neigh SURE thresholding, Image decomposing, Image processing, LabVIEW.
most current solution to overcome the shortcoming of the Short time Fourier transform. The use of fully scalable modulated window resolves the signal cutting problem. The window is shifted next to the signal and for every spot spectrum is calculated. Then this process is repeated numerous times with slightly shorter or longer window for each new cycle then the result is time frequency collection of the signal all with different resolution. By using varying window, one can deal resolution in time for resolution in frequency. In order to separate discontinuity in signal requires short basis function and for fine frequency analysis requires long low frequency basis function. This is realize by wavelet transforms where the basis functions are obtained from a single model wavelet by shift and extraction/ contraction 
We proposed a learning-based adaptive hard thresholding scheme to overcome the short- comings of using fixed hard thresholding in BM3D. We used the random forest classifier to train image blocks with their corresponding best threshold value. For any test image, we pre- dicted each image block’s best threshold value and use that threshold value in the collaborative filtering step of BM3D. We have also incorporated additive white Gaussian noise estimation method in our proposed method. The original BM3D relies on a user provided noise level while our method automatically calculates the noise level from a noisy image. Experimental result shows that we have achieved a significant improvement over the original algorithm both by subjective and objective measurement metrics. Our algorithm provides better denoising performance in terms of the PSNR and the SSIM. We have also showed visual quality compar- isons for various test images and found that our method achieved significant improvement over
Another method which has been used is FFT baseddenoising. Here, the Fourier transform is performed on the signal and then values of fourier coefficients which are below particular threshold are made to zero. Underlying the application of the technique is the supposition that in the frequency domain, the signal occupies a definite portion of the spectrum, most of the noise is outside this range of the frequency and the removal of noise in the wide range of frequencies result in the denoised signal.
Redundant (non-orthogonal) wavelet representations may be more suited to imagedenoising appli- cations since redundant representation of the image features may make the signal inherent relations clearer. Specifically, some redundant representations are designed to be translation or rotation in- variant (Freeman and Adelson, 1991; Coifman and Donoho, 1995; Kingsbury, 2006). This behavior is convenient to ensure that a particular feature in different spatial regions (or with different orienta- tions) gives rise to the same neighboring relations. Some translation invariant wavelets (Simoncelli and Freeman, 1995) have also a smoother rotation behavior than non-redundant transforms. This justifies applying the same processing all over a particular subband and dealing with the different orientations in similar ways. Besides, this prevents aliasing artifacts appearing in critically-sampled wavelets. In this work we choose a redundant steerable pyramid representation (Simoncelli and Freeman, 1995) to take advantage of these properties.
In medical field the ultrasound images are commonly used. There are many issue in the medical images due to introduction of noise. The speckle noise effects the quality of the image. It degrades the image in several ways. It makes many information invisible which is required for the diagnosis purpose. There are many methods to make the required information visible In this paper the study of different methods are adapted which compensate the speckle noise.
ABSTRACT:As digital images increased, the need of image retrieval also increased. Graph construction for capturing perceptual grouping cues of an image is important for graph basedimagesegmentation. Basic CBIR system capture only the local visual feature, thus to coverthe gap between local feature and high level visual perception we proposed this system.This technique introduces graph-basedimagesegmentation method in order to retrieve thecontent-based images. In this CBIR system first, query image get over-segmented, in whichthe many regions (or super-pixels) with homogeneous color are detected, imagesegmentation is performed by iteratively merging the regions according to a statistical test. Affinitygraph construction is there for building a graph from super-pixels. Furthermore, the imageSegmentation problem is solved by computing the partitions of a graph obtain from previousaffinity graph which result into sub-graphs. Finally graph edit distance is used for graphmatching between query image and database images. Then images with smallest edit costsare retrieved and display relevant result to user. Experiments on Corel Photo collection areconducted to demonstrate the performance of the proposed content basedimage retrieval algorithm. To elaborate the effectiveness of the presented work, the proposed method is compared with existing CBIR systems, and it is proved that the proposed method has performedbetter then all of the comparative systems.
Image Acquisition is to acquire a digital image. To do so requires an image sensor and the capability to digitize the signal produced by the sensor. The sensor could be monochrome or color TV camera that produces an entire image of the problem domain every 1/30 sec. the image sensor could also be line scan camera that produces a single image line at a time. In this case, the objects motion past the line.
Many researchers study this model for segmentation and classification (as discussed elsewhere in [12, 13, 17]). Lu in  extracts Wold feature for unsupervised texture segmen- tation, but he adapts the clustering method by combining Wold feature with wavelet features and MRSAR parameter features. In , di ﬀ erent types of image features are aggre- gated for classification by using a Bayesian probabilistic ap- proach. In , rotation and scaling invariant parameters are used. A tested texture image can be correctly classified even if it is rotated and scaled. In this paper, we will incorporate Wold decomposition into Bayesian framework as structural prior information.
In this article, RPCGNF-OAMNHA-CT technique is proposed for removing the noisy pixels from the images and reconstructing the noise-free images. In this technique, the images considered in the CT domain are given to the recurrent mechanism based PCGNF edge detector for segmenting and extracting the edge regions and homogeneous texture regions. The main aim of applying recurrent mechanism is creating the PCGNF system for edge-preserving segmentation that learns the parameters used in the segmentation with high efficiency and speeding up the convergence. So, the edge regions and homogeneous textures are synchronously segmented as noisy pixels until either the PCGNF converges to the maximum accuracy of segmentation or a termination criterion is reached. Moreover, OAMNHA is applied on each segmented regions to remove the noisy pixels and obtain the noiseless images precisely. Finally, the experimental results proved that the RPCGNF-OAMNHA-CT technique has maximum PSNR, SSIM and minimum MAE than the NF-OAMNHA-CT technique for imagedenoising.
perspective of textons to find these self- similarities through considering all arrangements of textons with touching pixels on a 2 x 2 system. By looking the above and after incredible know at the upsides of dim stage textons and morphology the present idea made "Morphological Model of Gray Level Textons"(MM-GLT) for smoke surfaces division. The proposed MM-GLT is in like manner significant to stage other sort of surfaces. Key words:-Segmentation, Edge Detection, Region Based, threshold-basedsegmentation techniques
Imagesegmentation methods fall into five categories: Pixel basedsegmentation , Region basedsegmentation , Edge basedsegmentation , , Edge and region Hybrid segmentation  and Clustering basedsegmentation , , , , , and monochrome segmentation. Color imagesegmentationusing fuzzy classification is a pixel basedsegmentation method. A pixel is assigned a specific color by the fuzzy system. Our approach in designing such a fuzzy system is to study the HSV color space and try to manually develop a set of fuzzy rules. The imagesegmentationusing colors is more preferred than gray color space because former method is perceptible by human eye and one can easily determine the difference in the resulting color segmented outputs clearly. Compared to gray scale, color provides information in addition to intensity. Color is useful or even necessary for pattern recognition and computer vision. Also the acquisition and processing hardware for color images have become more available and accessible to deal with the computational complexity caused by the high dimensional color space. Hence color image processing has become increasingly more practical.