Eigenstructure-based coherence attributes are efficient and mature techniques for large-scale fracture detection. However, in horizontally bedded and continuous strata, buried fractures in high grayscale value zones a...Eigenstructure-based coherence attributes are efficient and mature techniques for large-scale fracture detection. However, in horizontally bedded and continuous strata, buried fractures in high grayscale value zones are difficult to detect. Furthermore, middleand small-scale fractures in fractured zones where migration image energies are usually not concentrated perfectly are also hard to detect because of the fuzzy, clouded shadows owing to low grayscale values. A new fracture enhancement method combined with histogram equalization is proposed to solve these problems. With this method, the contrast between discontinuities and background in coherence images is increased, linear structures are highlighted by stepwise adjustment of the threshold of the coherence image, and fractures are detected at different scales. Application of the method shows that it can also improve fracture cognition and accuracy.展开更多
Since image real-time processing requires vast amount of computation and high-speed hardware,it is difficult to be implemented with general microcomputer system. In order to solve the problem,a powerful digital signal...Since image real-time processing requires vast amount of computation and high-speed hardware,it is difficult to be implemented with general microcomputer system. In order to solve the problem,a powerful digital signal processing (DSP) hardware system is proposed,which is able to meet needs of image real-time processing.There are many approaches to enhance infrared image.But only histogram equalization is discussed because it is the most common and effective way.On the basis of histogram equalization principle,the specific procedures implemented in DSP are shown.At last the experimental results are given.展开更多
Aimed at the two problems of underwater imaging, fog effect and color cast, an Improved Segmentation Dark Channel Prior(ISDCP) defogging method is proposed to solve the fog effects caused by physical properties of wat...Aimed at the two problems of underwater imaging, fog effect and color cast, an Improved Segmentation Dark Channel Prior(ISDCP) defogging method is proposed to solve the fog effects caused by physical properties of water. Due to mass refraction of light in the process of underwater imaging, fog effects would lead to image blurring. And color cast is closely related to different degree of attenuation while light with different wavelengths is traveling in water. The proposed method here integrates the ISDCP and quantitative histogram stretching techniques into the image enhancement procedure. Firstly, the threshold value is set during the refinement process of the transmission maps to identify the original mismatching, and to conduct the differentiated defogging process further. Secondly, a method of judging the propagating distance of light is adopted to get the attenuation degree of energy during the propagation underwater. Finally, the image histogram is stretched quantitatively in Red-Green-Blue channel respectively according to the degree of attenuation in each color channel. The proposed method ISDCP can reduce the computational complexity and improve the efficiency in terms of defogging effect to meet the real-time requirements. Qualitative and quantitative comparison for several different underwater scenes reveals that the proposed method can significantly improve the visibility compared with previous methods.展开更多
Aiming at the problem in infrared image enhancement,a new method is given based on histogram.Using the gray characteristics of target,the upper-bound threshold is selected adaptively and the histogram is processed by ...Aiming at the problem in infrared image enhancement,a new method is given based on histogram.Using the gray characteristics of target,the upper-bound threshold is selected adaptively and the histogram is processed by the threshold.After choosing the gray transform function based on the gray level distribution of image,the gray transformation is done during histogram equalization.Finally,the enhanced image is obtained.Compared with histogram equalization(HE),histogram double equalization(HDE) and plateau histogram equalization(PE),the simulation results demonstrate that the image enhancement effect of this method has obvious superiority.At the same time,its operation speed is fast and real-time ability is excellent.展开更多
An efficient novel algorithm was developed to estimate the Density of States(DOS) for large systems by calculating the ensemble means of an extensive physical variable, such as the potential energy, U, in generalized ...An efficient novel algorithm was developed to estimate the Density of States(DOS) for large systems by calculating the ensemble means of an extensive physical variable, such as the potential energy, U, in generalized canonical ensembles to interpolate the interior reverse temperature curve β_s(U)=SU/U, where S(U) is the logarithm of the DOS. This curve is computed with different accuracies in different energy regions to capture the dependence of the reverse temperature on U without setting prior grid in the U space. By combining with a U-compression transformation, we decrease the computational complexity from O(N3/2) in the normal Wang Landau type method to O(N1/2) in the current algorithm, as the degrees of freedom of system N. The efficiency of the algorithm is demonstrated by applying to Lennard Jones fluids with various N, along with its ability to find different macroscopic states, including metastable states.展开更多
基金sponsored by the National Science&Technology Major Special Project(Grant No.2011ZX05025-001-04)
文摘Eigenstructure-based coherence attributes are efficient and mature techniques for large-scale fracture detection. However, in horizontally bedded and continuous strata, buried fractures in high grayscale value zones are difficult to detect. Furthermore, middleand small-scale fractures in fractured zones where migration image energies are usually not concentrated perfectly are also hard to detect because of the fuzzy, clouded shadows owing to low grayscale values. A new fracture enhancement method combined with histogram equalization is proposed to solve these problems. With this method, the contrast between discontinuities and background in coherence images is increased, linear structures are highlighted by stepwise adjustment of the threshold of the coherence image, and fractures are detected at different scales. Application of the method shows that it can also improve fracture cognition and accuracy.
文摘Since image real-time processing requires vast amount of computation and high-speed hardware,it is difficult to be implemented with general microcomputer system. In order to solve the problem,a powerful digital signal processing (DSP) hardware system is proposed,which is able to meet needs of image real-time processing.There are many approaches to enhance infrared image.But only histogram equalization is discussed because it is the most common and effective way.On the basis of histogram equalization principle,the specific procedures implemented in DSP are shown.At last the experimental results are given.
基金supported by the National Natural Science Foundation of China (No. 61401413)
文摘Aimed at the two problems of underwater imaging, fog effect and color cast, an Improved Segmentation Dark Channel Prior(ISDCP) defogging method is proposed to solve the fog effects caused by physical properties of water. Due to mass refraction of light in the process of underwater imaging, fog effects would lead to image blurring. And color cast is closely related to different degree of attenuation while light with different wavelengths is traveling in water. The proposed method here integrates the ISDCP and quantitative histogram stretching techniques into the image enhancement procedure. Firstly, the threshold value is set during the refinement process of the transmission maps to identify the original mismatching, and to conduct the differentiated defogging process further. Secondly, a method of judging the propagating distance of light is adopted to get the attenuation degree of energy during the propagation underwater. Finally, the image histogram is stretched quantitatively in Red-Green-Blue channel respectively according to the degree of attenuation in each color channel. The proposed method ISDCP can reduce the computational complexity and improve the efficiency in terms of defogging effect to meet the real-time requirements. Qualitative and quantitative comparison for several different underwater scenes reveals that the proposed method can significantly improve the visibility compared with previous methods.
文摘Aiming at the problem in infrared image enhancement,a new method is given based on histogram.Using the gray characteristics of target,the upper-bound threshold is selected adaptively and the histogram is processed by the threshold.After choosing the gray transform function based on the gray level distribution of image,the gray transformation is done during histogram equalization.Finally,the enhanced image is obtained.Compared with histogram equalization(HE),histogram double equalization(HDE) and plateau histogram equalization(PE),the simulation results demonstrate that the image enhancement effect of this method has obvious superiority.At the same time,its operation speed is fast and real-time ability is excellent.
基金supported by the National Natural Science Foundation of China(Grant No.11175250)the Open Project Grant from the StateKey Laboratory of Theoretical PhysicsZhou X thanks the financial support of the Hundred of Talents Program in Chinese Academy of Sciences
文摘An efficient novel algorithm was developed to estimate the Density of States(DOS) for large systems by calculating the ensemble means of an extensive physical variable, such as the potential energy, U, in generalized canonical ensembles to interpolate the interior reverse temperature curve β_s(U)=SU/U, where S(U) is the logarithm of the DOS. This curve is computed with different accuracies in different energy regions to capture the dependence of the reverse temperature on U without setting prior grid in the U space. By combining with a U-compression transformation, we decrease the computational complexity from O(N3/2) in the normal Wang Landau type method to O(N1/2) in the current algorithm, as the degrees of freedom of system N. The efficiency of the algorithm is demonstrated by applying to Lennard Jones fluids with various N, along with its ability to find different macroscopic states, including metastable states.
