High-resolution imaging of synthetic aperture interferometric radiometry (SAIR) has been a research hotspot. Since the spatial resolution of SAIR is limited by array aperture size and the inversion process is a pathol...
详细信息
Imaging Atmospheric Cherenkov Telescopes (IACTs) enable precise ground-based observations of the gamma-ray sky by imaging the distribution of Cherenkov light emitted during the development of air showers. Nowadays, ma...
详细信息
Seismic surveys are often affected by irregularity and coarse sampling resulting from limitations at the acquisition such as obstacles and environmental constraints. Thus, various processing algorithms have been devel...
详细信息
In the actual industrial production process, we often encounter two or more kinds of objects mixed flow conditions, this phenomenon is generally known as multiphase flow in academia and industry. Process Tomography (P...
详细信息
Computed tomography (CT) technology plays an important role in the field of medicine. It helps the doctor give the accurately judgement of lesions through the clear CT image. But the patients can't afford a large ...
详细信息
Drone-based land surveys and tracking applications with a moving camera require three-dimensional reconstructions from videos recorded using a downward facing camera and are usually generated by Structure-from-Motion ...
详细信息
ISBN:
(纸本)9798350318920;9798350318937
Drone-based land surveys and tracking applications with a moving camera require three-dimensional reconstructions from videos recorded using a downward facing camera and are usually generated by Structure-from-Motion (SfM) algorithms. Unfortunately, monocular SfM pipelines can fail in the presence of lens distortion due to a critical configuration resulting in a plane-sphere ambiguity which is characterized by severe curvatures of the reconstructions and erroneous relative camera pose estimations. We propose a 4-point minimal solver for the relative pose estimation for two views sharing the same radial distortion parameters (i.e. from the same camera) with a viewing direction perpendicular to the ground plane. To extract 3D reconstructions from continuous videos, the relative pose of pairwise frames is estimated by using the solver with RANSAC and the Sampson error where globally consistent distortion parameters are determined by taking the medial of all values. Moreover, we propose an additional regularizer for the final bundle adjustment to remove any remaining curvature of the reconstruction if necessary. We tested our methods on synthetic and real-world data and our results demonstrate a significant reduction of curvature and more accurate relative pose estimations. Our algorithm can be easily integrated into existing pipelines and is therefore a practical solution to resolve the plane-sphere ambiguity in a variety of top-down SfM applications.
Phase-contrast CT (PCCT) is an emerging tool that has found numerous applications, including applications to preclinical imaging. There remains a need for reducing the imaging time in current PCCT. One approach to red...
详细信息
In the framework of the digital era, the technology of image processing is one of the technologies that is being used increasingly often in all aspects of modern life. image correction may be handled using algorithms ...
详细信息
Transformer-based models have been widely and successfully used in various low-vision visual tasks, and have achieved remarkable performance in single image super-resolution (SR). Despite the significant progress in S...
ISBN:
(纸本)9781956792041
Transformer-based models have been widely and successfully used in various low-vision visual tasks, and have achieved remarkable performance in single image super-resolution (SR). Despite the significant progress in SR, Transformer-based SR methods (e.g., SwinIR) still suffer from the problems of heavy computation cost and low-frequency preference, while ignoring the reconstruction of rich high-frequency information, hence hindering the representational power of Transformers. To address these issues, in this paper, we propose a novel Frequency-aware Transformer (FreqFormer) for lightweight image SR. Specifically, a Frequency Division Module (FDM) is first introduced to separately handle high- and low-frequency information in a divide-and-conquer manner. Moreover, we present Frequency-aware Transformer Block (FTB) to extracting both spatial frequency attention and channel transposed attention to recover high-frequency details. Extensive experimental results on public datasets demonstrate the superiority of our FreqFormer over state-of-the-art SR methods in terms of both quantitative metrics and visual quality. Code and models are available at https://***/JPWang-CS/FreqFormer.
imagereconstruction for positron emission tomography (PET) is challenging because of the ill-conditioned tomographic problem and low counting statistics. Kernel methods address this challenge by using kernel represen...
详细信息
ISBN:
(数字)9781510649408
ISBN:
(纸本)9781510649408;9781510649392
imagereconstruction for positron emission tomography (PET) is challenging because of the ill-conditioned tomographic problem and low counting statistics. Kernel methods address this challenge by using kernel representation to incorporate image prior information in the forward model of iterative PET imagereconstruction. Existing kernel methods construct the kernels commonly using an empirical procedure, which may lead to suboptimal performance. In this paper, we describe the equivalence between the kernel representation and a trainable neural network model. A deep kernel method is proposed with the training process utilizing available image prior to seek the best way to form a set of robust kernels optimally rather than empirically. The results from computer simulations and a real patient dataset demonstrate that the proposed deep kernel method can outperform existing kernel method and neural network method for dynamic PET imagereconstruction.
暂无评论