图象数据分层(Image Data Hierarchy)处理技术在图象数据压缩编码、边缘检测、特征提取以及模式识别中有着广泛的应用.本文将模糊聚类方法引入图象分层中,根据图象的特点,将2×2象素块划分为包含均匀和轮廓部分的七种类型,建立了表...图象数据分层(Image Data Hierarchy)处理技术在图象数据压缩编码、边缘检测、特征提取以及模式识别中有着广泛的应用.本文将模糊聚类方法引入图象分层中,根据图象的特点,将2×2象素块划分为包含均匀和轮廓部分的七种类型,建立了表征图象特征的相似度矩阵,修正了普通的动态聚类法,提出了λ值的自适应控制方案.最后,给出了对一幅标准“USC Girl”数字图象处理的实例以验证本方案的可行性.展开更多
Inundation of the Three Gorges Reservoir has created a 30-m water-level fluctuation zone with seasonal hydrological alternations of submergence and exposure, which may greatly affect soil properties and bank stability...Inundation of the Three Gorges Reservoir has created a 30-m water-level fluctuation zone with seasonal hydrological alternations of submergence and exposure, which may greatly affect soil properties and bank stability. The aim of this study was to investigate the response of soil pore structure to seasonal water-level fluctuation in the reservoir, and particularly, the hydrological change of wetting and drying cycles. Soil pore structure was visualized with industrial X-ray computed tomography and digital image analysis techniques. The results showed that soil total porosity(? 100 ?m), total pore number, total throat number, and mean throat surface area increased significantly under wetting and drying cycles. Soil porosity, pore number and throat numberwithin each size class increased in the course of wetting and drying cycles. The coordination number, degree of anisotropy and fractal dimension were indicating an increase. In contrast, the mean shape factor, pore-throat ratio, and Euler-Poincaré number decreased due to wetting and drying cycles. These illustrated that the wetting and drying cycles made soil pore structure become more porous, continuous, heterogeneous and complex. It can thus be deduced that the water-level fluctuation would modify soil porosity, pore size distribution, and pore morphology in the Three Gorges Reservoir, which may have profound implications for soil processes, soil functions, and bank stability.展开更多
A method of removing the airway from pulmonary segmentation image was proposed. This method firstly segments the image into several separate regions based on the optimum threshold and morphological operator, and then ...A method of removing the airway from pulmonary segmentation image was proposed. This method firstly segments the image into several separate regions based on the optimum threshold and morphological operator, and then each region is labeled and noted with its mean grayscale. Therefore, most of the non-lung regions can be removed according to the tissue’s Hounsfield units (HU) and the imaging modality. Finally, the airway region is recognized and deleted automatically through using the priori information of its HU and size. This proposed method is tested using several clinical images, yielding satisfying results.展开更多
A new method for forecasting non stationary series is developed. Its steps are as follows: Step 1. Data delaminating. Non stationary series is delaminated into several multi scale steady data layers and one trend laye...A new method for forecasting non stationary series is developed. Its steps are as follows: Step 1. Data delaminating. Non stationary series is delaminated into several multi scale steady data layers and one trend layer. Step 2. Modeling and forecasting each stationary data layer. Step 3. Imitating trend layer using polynomial. Step 4. Combining the forecasting layers and imitating layer into one series. The EMD (Empirical Mode Decomposition) method suitable to process non stationary series is selected to delaminate data, while ARMA (Auto Regressive Moving Average) model is employed to model and forecast stationary data layer and least square error method for trend layer regression. Aiming at forecasting length, forecasting orientation and selective method, experiments are performed for SAR (Synthetic Aperture Radar) images. Finally, an example is provided, in which the whole SAR image is restored via the method proposed by this paper.展开更多
A novel adaptive blind image watermarking scheme resistant to Rotation, scaling and translation (RST) attacks is proposed in this paper. Based on fuzzy clustering theory and Human visual system (HVS) model, the spread...A novel adaptive blind image watermarking scheme resistant to Rotation, scaling and translation (RST) attacks is proposed in this paper. Based on fuzzy clustering theory and Human visual system (HVS) model, the spread spectrum watermark is adaptively embedded in Discrete wavelet transform (DWT) domain. In order to register RST transform parameters, a hierarchical neural network is utilized to learn image geometric pattern represented by low order Zernike moments. Watermark extraction is carried out after watermarked image has been synchronized without original image. It only needs a trained neural network.Experiments show that it can embed more robust watermark under certain visual distance, effectively resist Joint photographic experts group (JPEG) compression, noise and RST attacks.展开更多
Segmentation of the bladder in computerized tomography(CT) images is an important step in radiation therapy planning of prostate cancer. We present a new segmentation scheme to automatically delineate the bladder cont...Segmentation of the bladder in computerized tomography(CT) images is an important step in radiation therapy planning of prostate cancer. We present a new segmentation scheme to automatically delineate the bladder contour in CT images with three major steps. First,we use the mean shift algorithm to obtain a clustered image containing the rough contour of the bladder,which is then extracted in the second step by applying a region-growing algorithm with the initial seed point selected from a line-by-line scanning process. The third step is to refine the bladder contour more accurately using the rolling-ball algorithm. These steps are then extended to segment the bladder volume in a slice-by-slice manner. The obtained results were compared to manual segmentation by radiation oncologists. The average values of sensitivity,specificity,positive predictive value,negative predictive value,and Hausdorff distance are 86.5%,96.3%,90.5%,96.5%,and 2.8 pixels,respectively. The results show that the bladder can be accurately segmented.展开更多
文摘图象数据分层(Image Data Hierarchy)处理技术在图象数据压缩编码、边缘检测、特征提取以及模式识别中有着广泛的应用.本文将模糊聚类方法引入图象分层中,根据图象的特点,将2×2象素块划分为包含均匀和轮廓部分的七种类型,建立了表征图象特征的相似度矩阵,修正了普通的动态聚类法,提出了λ值的自适应控制方案.最后,给出了对一幅标准“USC Girl”数字图象处理的实例以验证本方案的可行性.
基金funded by the National Natural Science Foundation of China(Grant No.41771321,41771320 and 41571278)Sichuan Science and Technology Program(Grant No.2018SZ0132)
文摘Inundation of the Three Gorges Reservoir has created a 30-m water-level fluctuation zone with seasonal hydrological alternations of submergence and exposure, which may greatly affect soil properties and bank stability. The aim of this study was to investigate the response of soil pore structure to seasonal water-level fluctuation in the reservoir, and particularly, the hydrological change of wetting and drying cycles. Soil pore structure was visualized with industrial X-ray computed tomography and digital image analysis techniques. The results showed that soil total porosity(? 100 ?m), total pore number, total throat number, and mean throat surface area increased significantly under wetting and drying cycles. Soil porosity, pore number and throat numberwithin each size class increased in the course of wetting and drying cycles. The coordination number, degree of anisotropy and fractal dimension were indicating an increase. In contrast, the mean shape factor, pore-throat ratio, and Euler-Poincaré number decreased due to wetting and drying cycles. These illustrated that the wetting and drying cycles made soil pore structure become more porous, continuous, heterogeneous and complex. It can thus be deduced that the water-level fluctuation would modify soil porosity, pore size distribution, and pore morphology in the Three Gorges Reservoir, which may have profound implications for soil processes, soil functions, and bank stability.
文摘A method of removing the airway from pulmonary segmentation image was proposed. This method firstly segments the image into several separate regions based on the optimum threshold and morphological operator, and then each region is labeled and noted with its mean grayscale. Therefore, most of the non-lung regions can be removed according to the tissue’s Hounsfield units (HU) and the imaging modality. Finally, the airway region is recognized and deleted automatically through using the priori information of its HU and size. This proposed method is tested using several clinical images, yielding satisfying results.
文摘A new method for forecasting non stationary series is developed. Its steps are as follows: Step 1. Data delaminating. Non stationary series is delaminated into several multi scale steady data layers and one trend layer. Step 2. Modeling and forecasting each stationary data layer. Step 3. Imitating trend layer using polynomial. Step 4. Combining the forecasting layers and imitating layer into one series. The EMD (Empirical Mode Decomposition) method suitable to process non stationary series is selected to delaminate data, while ARMA (Auto Regressive Moving Average) model is employed to model and forecast stationary data layer and least square error method for trend layer regression. Aiming at forecasting length, forecasting orientation and selective method, experiments are performed for SAR (Synthetic Aperture Radar) images. Finally, an example is provided, in which the whole SAR image is restored via the method proposed by this paper.
文摘A novel adaptive blind image watermarking scheme resistant to Rotation, scaling and translation (RST) attacks is proposed in this paper. Based on fuzzy clustering theory and Human visual system (HVS) model, the spread spectrum watermark is adaptively embedded in Discrete wavelet transform (DWT) domain. In order to register RST transform parameters, a hierarchical neural network is utilized to learn image geometric pattern represented by low order Zernike moments. Watermark extraction is carried out after watermarked image has been synchronized without original image. It only needs a trained neural network.Experiments show that it can embed more robust watermark under certain visual distance, effectively resist Joint photographic experts group (JPEG) compression, noise and RST attacks.
基金Project (No. 60675023) supported by the National Natural Science Foundation of China
文摘Segmentation of the bladder in computerized tomography(CT) images is an important step in radiation therapy planning of prostate cancer. We present a new segmentation scheme to automatically delineate the bladder contour in CT images with three major steps. First,we use the mean shift algorithm to obtain a clustered image containing the rough contour of the bladder,which is then extracted in the second step by applying a region-growing algorithm with the initial seed point selected from a line-by-line scanning process. The third step is to refine the bladder contour more accurately using the rolling-ball algorithm. These steps are then extended to segment the bladder volume in a slice-by-slice manner. The obtained results were compared to manual segmentation by radiation oncologists. The average values of sensitivity,specificity,positive predictive value,negative predictive value,and Hausdorff distance are 86.5%,96.3%,90.5%,96.5%,and 2.8 pixels,respectively. The results show that the bladder can be accurately segmented.
