Image Deblurring
| Mon, 16 Mar 2020 - herman | |
| Image Deblurring By Exploting Inherent Bi-Level Regions | |
| Po-Hao Huang, Yu-Mo Lin, Hao-Liang Yang, Shang-Hong Lai | |
| We propose an image restoration framework for restoring an image degraded by unknown motion blur. Our approach takes advantage of inherent bi-level regions of an image to estimate a blur kernel. The framework contains three parts: bi-level region searching, initial blur kernel estimation and iterative maximum a posteriori (MAP) image restoration. Firstly, candidate bi-level regions are located around the detected corners. We use four image features to score each region and choose the best N regions for estimating an initial blur kernel. Finally, an alternating minimization algorithm is developed to iteratively refine both the blur kernel and the restored image. Experimental results of synthetic and real blurred images are shown to demonstrate the performance of the proposed algorithm. |
| Fri, 20 Jul 2018 - intern_james | |
| Blind Image Deblurring with Modified Richardson-Lucy Deconvolution for Ringing Artifact Suppression | |
| Hao-Liang Yang, Yen-Hao Chiao, Po-Hao Huang, Shang-Hong Lai | |
| In this paper, we develop a unified image deblurring framework that consists of both blur kernel estimation and non-blind image deconvolution. For blind kernel estimation, we propose a patch selection procedure and integrate it with a coarse-to-fine kernel estimation algorithm to develop a robust blur kernel estimation algorithm. For the non-blind image deconvolution, we modify the traditional Richardson-Lucy (RL) image restoration algorithm to suppress the notorious ringing artifact in the regions around strong edges. Experimental results on some real blurred images are shown to demonstrate the improved efficiency and image restoration by using the proposed algorithm. |
Medical Imaging
| Mon, 23 Jul 2018 - intern_james | |
| Reconstruction of 3D Vertebrae and Spinal Cord Models from CT and STIR-MRI Images | |
| C. Yen, H.-R. Su and S.-H. Lai | |
| In this paper, we propose a system that integrates vertebrae, spinal cord and nerves segmentation results from STIR-MRI and CT images, by estimating the transformation relationship between the segmented vertebra models extracted from these two types of images. Since the segmentation results are already obtained, we build the 3D spinal cord and nerves model. Then we apply a deformable registration algorithm to register the pre-built 3D vertebra models in CT and STIR-MRI. Thus, we apply the local affine transformation to integrate STIR-MRI spinal cord and nerves information with CT vertebrae. This is accomplished by applying a linear interpolation method to achieve the purpose of local affine transformation. In the experimental results, we show the 3D segmentation results of spinal nerve from the STIR-MRI (Short Tau Inversion Recovery - Magnetic Resonance Imaging) images, and also show the integrated 3D spine models from CT and STIR-MRI images. |
| Mon, 23 Jul 2018 - intern_james | |
| 3D Liver Segmentation and Model Reconstruction from CT Images | |
| Y. Y. Cheng, H. M. Chang, H. R. Su, S. H. Lai, K. C. Liu and C. H. Lin. | |
| In this paper, we present a system for segmenting the 3D liver region from CT images and reconstructing its 3D model. The segmentation is accomplished in 3-D space which is extended from the user controlled 2-D random walker technique and implemented by a slice-section method. After obtaining the 3D liver segmentation result, we apply the surface reconstruction algorithm based on bipartite polar classification to build the 3-D liver surface model. In the experimental results, we apply the proposed algorithm to ten test CT datasets to evaluate its accuracy and we demonstrate the good accuracy compared with the human labeled results. |
| Mon, 23 Jul 2018 - intern_james | |
| 3D Spinal Cord and Nerves Segmentation from STIR-MRI | |
| C. Yen, H.R. Su, S.H. Lai, K.C. Liu, R.R. Lee | |
| In this paper, we present a system for spinal cord and nerves segmentation from STIR-MRI. We propose an user interactive segmentation method for 3D images, which is extended from the 2D random walker algorithm and implemented with a slice-section strategy. After obtaining the 3D segmentation result, we build the 3D spinal cord and nerves model for each view using VTK, which is an open-source, freely available software. Then we obtain the point cloud of the spinal cord and nerves surface by registering the three surface models constructed from three STIR-MRI images of different directions. In the experimental results, we show the 3D segmentation results of spinal cord and nerves from the STIR-MRI (Short Tau Inversion Recovery - Magnetic Resonance Imaging)images in three different views, and also display the reconstructed 3D surface model. Istanbul Escorts is one of the most important cities in Turkey and is visited by millions of tourists every year. istanbul escort services are also offered in Istanbul to meet the needs of domestic and foreign tourists traveling to Istanbul. Escort services are very popular in Istanbul. Therefore, the competition of services is quite high. istanbul escort agencies are the leaders in escort services in Istanbul. Clients can purchase escort services from reliable escort agencies in Istanbul. Umraniye escort is a district located on the Anatolian Side of Istanbul and has been developing rapidly in recent years. This development has led to the opening of many new businesses in the district and the provision of services. umraniye escort agencies, which are among these businesses, are one of the Decently preferred services in Umraniye. Escort agencies in Umraniye have escort girls with different features and different service options. umraniye escort For this reason, the people who will receive services need to choose the most suitable escort girl for them first. Many people who want to get an escort service want to meet escort girls who offer quality services. umraniye escort agencies in Umraniye host escort girls who offer high standards of service in line with the demands of their clients. Sisli Escort services is a sector where women who offer quality escort services take part. sisli eskort In this service, it is possible to make a preference among local or foreign women. Dec. Izmir Escorts services can also be purchased in different packages offered to the client. izmir escort For example, different options may be offered as an overnight service package, a several-hour service package, or a full-day service package. istanbul escorts girls website, istanbul escorts female profiles. You can reach nightly and hourly escorts female partner advertisements 24/7. Girls in Georgia escorts in Tbilisi escorts in Batumi escorts in Kutaisi escorts in Poti escorts in Rustavi VIP escorts Girls in batumi escorts in Batumi offer escorts service and erotic massage. Tbilisi and call girls from escorts agencies are waiting you. Mecidiyekoy Escort is a neighborhood located on the Anatolian Side of Istanbul, where various activities and nightlife are busy. One service that takes part in this eventful life is the escort service. mecidiyekoy escort services are provided by many women who live in this neighborhood and offer this service. The latest istanbul escorts girls profiles on our Istanbul escorts site. Taksim escorts site, taksim escorts lady and istanbul escorts girl profiles. The services offered by the escort girls of Sisli are offered entirely according to the wishes of the clients. sisli escort These services include accompaniment services in general, attending special events, services for physical Decoupling, massage services and many different requests. Misty Escorts services offer many services, including sexually explicit services. sisli escort These services are arranged according to the demands of the customers. Sisli Escorts services can also offer personalized services according to the clients requests. sisli escort Sisli Escort is one of the largest cities in Turkey and there are many escort services offered in this city. Sisli Escorts Taksim Escort services have become quite popular in recent years. Due to the fact that Taksim is one of the largest districts of Istanbul, taksim escort there are many businesses offering Taksim Escorts services here. |
| Fri, 20 Jul 2018 - intern_james | |
| Texture Feature Analysis of Ultrasonic Images with Wryneck | |
| Hsiao-Mei Chang, Ya-Yun Cheng, Hong-Ren Su, Shang-Hong Lai, Chu-Hsu Lin, and Hung-Chih Hsu | |
| Torticollis, also called wryneck, is a clinical sign or symptom that could be the result of a variety of possible disorders. Among the etiologies, congenital muscular torticollis (CMT) with impairment of the sternocleidomastoid (SCM) is the most frequent cause of torticollis in infants. Infants with CMT have the symptom of head tilt to one side, which is often combined with rotation of the head to the opposite side. In this paper, we report a study on the analysis of the ultrasonic images on two sides of the neck for the CMT classification. To this end, we first apply an interactive ROI segmentation procedure, followed by the extraction of several different texture features for the classification of CMT type. We use three types of texture features, including gray-lever co-occurrence matrix, Laplacian of Gaussian, and Gabor features. In addition, three feature comparison methods, such as mutual information, Bhattacharyya Distance, and Kullback-Leibler divergence, are used to compute the distribution distances for different texture features and feed them into the support vector machine classifier for the CMT classification. Experimental results demonstrate the performance of the proposed image analysis and classification method on real ultrasonic images. |
| Fri, 20 Jul 2018 - intern_james | |
| CT-MR image registration in 3D K-Space based on Fourier moment matching | |
| H.-R. Su and S.-H. Lai | |
| CT-MRI registration is a common processing procedure for clinical diagnosis and therapy. We propose a novel K-space affine image registration algorithm via Fourier moment matching. The proposed algorithm is based on estimating the affine matrix from the moment relationship between the corresponding Fourier spectrums. This estimation strategy is very robust because the energy of the Fourier spectrum is mostly concentrated in the low-frequency band, thus the moments of the Fourier spectrum are robust against noises and outliers. Our experiments on the real CT and MRI datasets show that the proposed Fourier-based registration algorithm provides higher registration accuracy than the existing mutual information registration technique. |
| Thu, 25 Nov 2010 - rily | |
| Compensation of Motion Artifacts in MRI via Graph-Based Optimization | |
| Tung-Ying Lee, Hong-Ren Su, Shang-Hong Lai, and Ti-chiun Chang | |
| In two-dimensional Fourier transform magnetic resonance imaging (2DFT-MRI), patient/object motion during the image acquisition results in ghosting and blurring. These motion artifacts are commonly considered as a major limitation in the MRI community. To correct these artifacts without resorting to additional navigator echoes, most existing methods perform image quality measure to estimate motion; but they may easily fail when the motion is large. Viewed as a blind image restoration problem where the motion point spread function (PSF) is unknown, state-of-the-art restoration algorithms can not be easily applied because they cannot handle a complex PSF kernel that has the same size as the image. To overcome these challenges, we propose a novel approach that exploits the image structure to segment the kernel into several fragments. Based on this kernel representation, determining a kernel fragment can be formulated as a binary optimization problem, where each binary variable represents whether a segment in MR signals is corrupted by a certain motion or not. We establish a graphical model for these variables and estimate the kernel by minimizing an energy functional associated with the model. Experimental results show that the proposed method can provide satisfactory compensation of motion artifacts even when large motions are involved in the MR images. |
OCR
Camera Calibration
| Mon, 23 Jul 2018 - intern_james | |
| Rolling shutter correction for video with large depth of field | |
| Yen-Hao Chiao, Tung-Ying Lee, Shang-Hong Lai | |
| Rolling shutter correction has attracted considerable attention in recent years. Several algorithms have been proposed to correct the distortion. Previous methods on rolling shutter correction did not consider depth variations in the scene. In this work, we overcome the limitation of the previous works that the depth of field in the scene is small. We present a correction model for rectifying the rolling shutter video based on the depth maps estimated from the rolling shutter video. In addition, we propose a two-stage optimization algorithm to estimate the temporal camera motion and the associated depth maps. Experimental results show the improvement of the proposed rolling shutter correction algorithm that takes the depth information into account. |
| Fri, 20 Jul 2018 - intern_james | |
| Real-Time Correction of Wide-Angle Lens Distortion for Images with GPU Computing | |
| Tung-Ying Lee, Chen-Hao Wei, Shang-Hong Lai, and Ruen-Rone Lee | |
| Wide-angle lens provides a broad field of view which benefits some applications, such as video surveillance or endoscopic imaging. However, it also induces lens distortion, especially radial distortion, which may impede further video analysis or perceptual interpretation. For some applications, such as minimally invasive surgery and visual surveillance, realtime correction of image distortion is required. Traditional CPU-centric machines are difficult to achieve the requirement of real-time computation because of a large amount of computation. In this paper, we propose to achieve real-time correction of wide-angle lens distortion of images on several target platforms. In the GPGPU platform, we achieve real-time correction at fullHD resolution by using CUDA. For middle-end devices, an error-controllable mesh is used and the system is implemented by industry standard, OpenGL. We also implement it with OpenGL ES on embedded GPUs for mobile devices. Experiments show using our error-controllable mesh greatly outperforms those using regularly downsampled meshes |
| Thu, 19 Jul 2018 - intern_james | |
| Wide Angle Distortion Correction by Hough Transform and Gradient Estimation | |
| T.-Y. Lee, T.-S. Chang, and S.-H. Lai | |
| Wide-angle cameras have been widely used in surveillance and endoscopic imaging. An automatic distortion correction method is very useful for these applications. Traditional methods extract corners or curved straight lines for estimating distortion parameters. Hough transform is a powerful tool to assess straightness. However, previous methods usually require some human intervention or only focus on using a single curve. In this paper, we propose a new method based on Hough transform by considering all curves into the estimation of distortion parameters. By considering the relationship between distortion parameters and curves, our method is fully automatic and does not require manual selection of curves in an image. Experiments on synthetic and real datasets have been conducted. The results of our method are also compared with other Hough Transform based methods in quantitative measures. The experimental results show that the accuracy of the proposed automatic method is comparable to those of other manual line-based methods. |