New Method for Field of View Extension or Frame-Rate Increase in Low-Coherence Off-Axis Holography

2014 ◽  
Author(s):  
Natan T. Shaked ◽  
Pinhas Girshovitz ◽  
Irena Frenklach
Keyword(s):  
Rate Increase ◽  
Field Of View ◽  
Frame Rate ◽  
New Method ◽  
Low Coherence

Comparison of two algorithms for the application of real-time image mosaicking in neuroendoscopy

2014 ◽  
Vol 121 (3) ◽  
pp. 688-699
Author(s):  
Kay Niklas Liebig ◽  
Homajoun Maslehaty ◽  
Athanasios K. Petridis ◽  
Wolfgang Konen ◽  
Martin Scholz
Keyword(s):  
Field Of View ◽  
Frame Rate ◽  
Neurosurgical Procedures ◽  
Surgical Safety ◽  
Area Of Interest ◽  
Image Mosaicking ◽  
Panoramic Images ◽  
The Creation ◽  
Endoscopic Methods

Object Neuroendoscopy is used more and more frequently in neurosurgical procedures and has become an important tool in the neurosurgical armamentarium. However, the main restriction of neuroendoscopy is the limited field of view. A better overview of the area of interest would increase surgical safety and decrease procedure-related morbidity rates. In the present study, the authors aimed to improve this restriction by using and comparing two algorithms to create endoscopic panoramic images, which increase the field of view during neuroendoscopic procedures. Methods Different endoscopic methods with or without a stand and with linear or circular endoscope movements were performed in cadaveric ventricles. Video of the endoscopy was used to create image mosaics of the lateral ventricle with the help of the Kourogi or LogSearch (LS) algorithm. In the LS algorithm, different template sizes were used. Three observers graded the quality of the image mosaic in terms of usefulness in surgery. The fastest frame rate was 3–4 frames/second. Results The LS algorithm with a larger template size showed significantly better results for the creation of image mosaics than the Kourogi algorithm in linear endoscopic movement with or without a stand. In circular endoscopic movements, the results seemed to be better with the LS algorithm but were not significantly different from those obtained with the Kourogi algorithm. In summary, image quality in the experimental paradigms was satisfying. Conclusions Results in the study showed that the creation of image mosaics is possible and reliable with the featured algorithms. Image mosaicking is an applicable device for neuroendoscopy and can increase the field of view during endoscopic procedures. Its use can increase the safety and the field of application of neuroendoscopy. However, faster frame rates will be required to create a smooth image for practical use during surgery.

Upconversion dark-field imaging with extended field of view at video frame rate

2020 ◽  
Vol 59 (7) ◽  
pp. 2157
Author(s):  
Saher Junaid ◽  
Peter Tidemand-Lichtenberg ◽  
Christian Pedersen ◽  
Peter John Rodrigo
Keyword(s):  
Dark Field ◽  
Field Of View ◽  
Frame Rate ◽  
Video Frame ◽  
Dark Field Imaging ◽  
Extended Field ◽  
Field Imaging ◽  
Video Frame Rate ◽  
Extended Field Of View

scholarly journals Doubling the field of view in off-axis low-coherence interferometric imaging

2014 ◽  
Vol 3 (3) ◽  
pp. e151-e151 ◽  
Author(s):  
Pinhas Girshovitz ◽  
Natan T Shaked
Keyword(s):  
Field Of View ◽  
Interferometric Imaging ◽  
Low Coherence

Improved Tooth Crown Edge Smoothing Method Based on Noise Classification and Fitting

2020 ◽  
Vol 10 (11) ◽  
pp. 2609-2619
Author(s):  
Tian Ma ◽  
Yurong Li
Keyword(s):  
3D Reconstruction ◽  
Least Squares ◽  
Rate Increase ◽  
Removal Rate ◽  
Noise Removal ◽  
New Method ◽  
Boundary Line ◽  
Tooth Crown ◽  
Least Squares Fitting ◽  
Noise Classification

Because three-dimensional (3D) models of teeth are currently obtained via oral scanning, there are only the tooth crown and gingival surface part, lack of data on the roots of teeth, which is not conducive to the 3D reconstruction of teeth. In order to help doctors to carry out virtual tooth correction, this paper studies the edge characteristics of the tooth crown model, removes the edge noise, which can better carry out the 3D reconstruction of teeth. Therefore, this paper proposes an improved method of tooth crown edge smoothing based on noise classification and fitting. First, according to the characteristics of the tooth crown edge, the method of noise classification is proposed after fitting analysis. The noise can be divided into two types: the noise in the boundary line and the noise in the fitting curve. Then, the noise can be identified according to the Gaussian curvature. Finally, the improved Laplacian smoothing and least squares fitting methods are used to remove the two types of noise, and the denoised tooth crown model is the output. The smoothing effect of the method is verified in terms of the noise removal rate, the patch filling rate, and the patch deletion rate. Compared with the traditional Laplacian smoothig, the new method exhibited a noise removal rate increase of 86.0%, a probability of patch filling that approximately doubled, and a probability of patch deletion that basically remained the same. Compared with the least squares fitting method, the new method exhibited a noise removal rate increase of 75.9%, a patch filling reduction of 22.61%, and a patch deletion reduction of 22.14%.

scholarly journals 3D Reconstruction of the Surface Using a Standard Camera

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Dalibor Martišek
Keyword(s):  
3D Reconstruction ◽  
Ccd Camera ◽  
Confocal Microscope ◽  
Phase Correlation ◽  
Field Of View ◽  
New Method ◽  
Small Field ◽  
Geometrical Transformation ◽  
Small Field Of View

This paper deals with3Dreconstructions of series of partially focussed images. Some of these methods are known in case of images which were acquired in small field of view (by confocal microscope or CCD camera, e.g.). In this case, recorded images do not differ in any geometrical transformation from each other. In case of larger samples (oversized for microscope or CCD camera), it is necessary to use wider viewing field (standard cameras, e.g.), and taken images primarily differ in scaling but may also differ in shifting and rotation too. These images cannot be used for reconstruction directly; they must be registered; that is, we must determine all transformations which the images differ and eliminate their effects. There are several ways to do this. This paper deals with the registration based on phase correlation. After this registration, it is necessary to identify the sharp parts and to compose a2Dand3Dmodel. Present methods are very sensitive to noise and their results are not satisfactory in many cases. We introduce a new method for3Dreconstruction which is significantly better.

scholarly journals Performance Improvement for Two-Lens Panoramic Endoscopic System during Minimally Invasive Surgery

2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Dinh Thai Kim ◽  
Ching Hwa Cheng ◽  
Don Gey Liu ◽  
Kai-Che Jack Liu ◽  
Shih Wei Wayne Huang ◽  
...  
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Performance Improvement ◽  
Invasive Surgery ◽  
Ground Truth ◽  
Previous Method ◽  
Field Of View ◽  
Frame Rate ◽  
Specular Reflections ◽  
Field Of Vision

One of the major challenges for Minimally Invasive Surgery (MIS) is the limited field of vision (FOV) of the endoscope. A previous study by the authors designed a MIS Panoramic Endoscope (MISPE) that gives the physician a broad field of view, but this approach is still limited, in terms of performance and quality because it encounters difficulty when there is smoke, specular reflections, or a change in viewpoint. This study proposes a novel algorithm that increases the MISPE’s performance. The method calculates the disparity for the region that is overlapped by the two cameras to allow image stitching. An improved evaluation of the homography matrix uses a frame-by-frame calculation, so the stitched videos are more stable for MIS. The experimental results show that the revised MISPE has a FOV that is 55% greater, and the system operates stably in real time. The proposed system allows a frame rate of 26.7 fps on a single CPU computer. The proposed stitching method is 1.55 times faster than the previous method. The stitched image that is obtained using the proposed method is as similar as the ground truth as the SURF-based stitching method that was used in the previous study.

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