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In this paper, we propose a novel autoregressive (AR) model based on the adaptive window and the patch-geodesic distance for the image interpolation. The model combines the information of inner/inter-patch correlation. To model the inner-patch correlation, we introduce a patch-geodesic distance similarity metric. The proposed metric shows the desirable capacity to depict the piecewise-stationarity...
Objective image quality metrics offer the prospect of adapting video processing algorithms to the quality of the incoming signal. In the context of image enhancement, such as peaking, contrast enhancement or color mapping, the original image does not necessarily correspond to the subjective optimum. There is, therefore, a compelling need for reliable quality metrics that are based exclusively on the...
Given a real world graph, how can we find a large subgraph whose partition quality is much better than the original? Graph partitioning has received great attentions in graph mining, and especially balanced graph partitioning is required in many real world applications. However, the balanced graph partitioning is known to be NP-hard, and moreover it is known that there is no good cut at a large scale...
Document image binarization is performed to segment foreground text from background text in badly degraded documents. In this paper, a comprehensive survey has been conducted on some state-of-the-art document image binarization techniques. After describing these document images binarization techniques, their performance have been compared with the help of various evaluation performance metrics which...
Achieving sub-pixel accuracy with face alignment algorithms is a difficult task given the diversity of appearance in real world facial profiles. To capture variations in perspective, occlusion, and illumination with adequate precision, current face alignment approaches rely on detecting facial landmarks and iteratively adjusting deformable models that encode prior knowledge of facial structure. However,...
Image sharpness measurements are important parts of many image processing applications. To measure image sharpness multiple algorithms have been proposed and measured in the past but they have been developed with having out-of-focus photographs in mind and they do not work so well with images taken using a digital microscope. In this article we show the difference between images taken with digital...
Synthetic Aperture Radar (SAR) is an active remote sensing technique. SAR is corrupted by a signal dependent multiplicative noise called speckle noise. Speckle noise limits the data extraction capabilities and degrades the quality of the obtained data. It decreases the potentiality to interpret the image, restricts edge abstraction, image segmentation, target recognition and classification. It is...
This paper presents an efficient approach to measure sharpness mismatches between stereoscopic views. Sharpness mismatch can occur through focus mismatches between stereoscopic cameras, errors in post-processing or even for low-bandwidth transmission, where one view is subsampled or transmitted at a much lower rate. This artifact can lead to a degraded 3D experience for observers. In this paper, the...
In the virtual-view 3D video coding system, both the RGB image data and the depth maps are compressed and translated to the receivers. After compression, the depth maps are distorted and may cause visible artifacts on the synthesized video. We study the visual effect of compressed depth maps on the synthesized video and develop a quality assessment model that predicts the subjective quality. We use...
Image fusion plays an important role in image enhancement and retrieval. For multi-focus image fusion as it is related to frequency distortion the wavelet with symmetric property is more useful to retrieve the image. Hence, to select the wavelet family, which provides better frequency resolution is of immense importance. Due to this property of haar and biorthogonal wavelet bases, they are used for...
Background modeling techniques are used for moving object detection in video. Many algorithms exist in the field of object detection with different purposes. In this paper, we propose an improvement of moving object detection based on codebook segmentation. We associate the original codebook algorithm with an edge detection algorithm. Our goal is to prove the efficiency of using an edge detection...
Simple and effective image quality assessment (IQA) method is very desirable in many image and video processing applications, such as coding, transmission, restoration and enhancement. Classic pixel absolute error based objective IQA metrics such as mean square error (MSE) and corresponding peak signal to noise ratio (PSNR) are widely used for various applications due to low computation and clear...
As technology advances; blur in an image remains as an ever-present issue in the image processing field. A blurred image is mathematically expressed as a convolution of a blur function with a sharp image, plus noise. Removing blur from an image has been widely researched and is still important as new images are collected. Without a reference image, identifying, measuring, and removing blur from a...
Edge preservation ratio (EPR) is a full-reference metric for objective image quality assessment (IQA). It is under the assumption that key messages to human visual systems are mainly from image structures, and these structures can be extracted by edge detection. EPR measure is twofold: accuracy and robustness, and a color map is synthesized to reveal structure changes before and after image processing...
Image blur assessment has always played an important role in the image quality assessment (IQA). In fact, many methods have been used to measure the blur of an image, but we find that lots of the traditional methods can't effectively compare the blur among images with different contents, leading to the blur measuring more difficult. Recently, we find a perfect method based on the idea that it is difficult...
In this paper we propose a hierarchy of techniques for performing loop closure in indoor environments together with an exploration strategy designed to reduce uncertainty in the resulting map. We use the generalized Voronoi graph to represent the indoor environment and an extended Kalman filter to track the pose of the robot and the position of the junctions (vertices) of the topological graph. Every...
Modularity is widely used to effectively measure the strength of the disjoint community structure found by community detection algorithms. Although several overlapping extensions of modularity were proposed to measure the quality of overlapping community structure, there is lack of systematic comparison of different extensions. To fill this gap, we overview overlapping extensions of modularity to...
Super resolution (SR) image reconstruction refers to a process of generating a high resolution image from several low resolution images. There is a high demand for highresolution satellite sensing in modern applications. SR offers an affordable solution for this high demand. The accuracy of super resolution depends on the accuracy of determining the difference between the low-resolution images. The...
We present our novel community mining algorithm that uses only local information to accurately identify communities, outliers, and hubs in social networks. The main component of our algorithm is the T metric, which evaluates the relative quality of a community by considering the number of internal and external triads (3-node cliques) it contains. Furthermore we propose an intuitive statistical method...
In previous work we demonstrated the use of temporal image sequences to identify broad land use classes [1, 2], relying on analysis at paddock rather than pixel scales. This paper describes a method to spatially segment a time-series stack of imagery to produce paddock units. Results are demonstrated on a significant portion of the Canterbury Plains where over 58,000 paddocks were identified. This...
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