Search results for "Computer Vision"
showing 10 items of 2353 documents
Feature Dimensionality Reduction for Mammographic Report Classification
2016
The amount and the variety of available medical data coming from multiple and heterogeneous sources can inhibit analysis, manual interpretation, and use of simple data management applications. In this paper a deep overview of the principal algorithms for dimensionality reduction is carried out; moreover, the most effective techniques are applied on a dataset composed of 4461 mammographic reports is presented. The most useful medical terms are converted and represented using a TF-IDF matrix, in order to enable data mining and retrieval tasks. A series of query have been performed on the raw matrix and on the same matrix after the dimensionality reduction obtained using the most useful techni…
Improving light propagation Monte Carlo simulations with accurate 3D modeling of skin tissue
2008
In this paper, we present a 3D light propagation model to simulate multispectral reflectance images of large skin surface areas. In particular, we aim to simulate more accurately the effects of various physiological properties of the skin in the case of subcutaneous vein imaging compared to existing models. Our method combines a Monte Carlo light propagation model, a realistic three-dimensional model of the skin using parametric surfaces and a vision system for data acquisition. We describe our model in detail, present results from the Monte Carlo modeling and compare our results with those obtained with a well established Monte Carlo model and with real skin reflectance images.
Vision system for defect imaging, detection, and characterization on a specular surface of a 3D object
2002
Abstract A vision system capable of imaging, detecting, and characterizing defects onto highly reflective, non-plane surfaces, is presented in this paper. Defects are typically dust, and hair located under the metallic layer of packaging products used in cosmetic industries. The vision system comprises an innovative lighting solution to reveal defects onto highly reflective non-plane surfaces. Several image acquisitions are performed to build a synthetic image, where defects clearly appear white on a mid-gray background. Our lighting system allows imaging defects on various-shaped objects. The vision system measures the defect size to make a decision on the product rejection. The authors as…
High-resolution far-field integral-imaging camera by double snapshot
2012
In multi-view three-dimensional imaging, to capture the elemental images of distant objects, the use of a field-like lens that projects the reference plane onto the microlens array is necessary. In this case, the spatial resolution of reconstructed images is equal to the spatial density of microlenses in the array. In this paper we report a simple method, based on the realization of double snapshots, to double the 2D pixel density of reconstructed scenes. Experiments are reported to support the proposed approach.
Tactile input of the hand and the control of reaching to grasp movements
1997
The role of tactile information of the hand in the control of reaching to grasp movements was investigated. The kinematics of both reaching (or transport) and grasp components were studied in healthy subjects in two experimental conditions. In one condition (control condition) subjects were required to reach and grasp an object that could have two sizes and that could be located at two distances from the viewer. In the other condition (anaesthesia condition) the same movements were executed, but anaesthesia was provided to the subjects' fingertips. In both conditions vision of the hand was prevented during movement. Anaesthesia affected mainly the kinematics of the first phase of grasping, …
Fully automatic multispectral MR image segmentation of prostate gland based on the fuzzy C-means clustering algorithm
2017
Prostate imaging is a very critical issue in the clinical practice, especially for diagnosis, therapy, and staging of prostate cancer. Magnetic Resonance Imaging (MRI) can provide both morphologic and complementary functional information of tumor region. Manual detection and segmentation of prostate gland and carcinoma on multispectral MRI data is not easily practicable in the clinical routine because of the long times required by experienced radiologists to analyze several types of imaging data. In this paper, a fully automatic image segmentation method, exploiting an unsupervised Fuzzy C-Means (FCM) clustering technique for multispectral T1-weighted and T2-weighted MRI data processing, is…
CultReal—A Rapid Development Platform for AR Cultural Spaces, with Fused Localization
2021
Virtual and augmented reality technologies have known an impressive market evolution due to their potential to provide immersive experiences. However, they still have significant difficulties to enable fully fledged, consumer-ready applications that can handle complex tasks such as multi-user collaboration or time-persistent experiences. In this context, CultReal is a rapid creation and deployment platform for augmented reality (AR), aiming to revitalize cultural spaces. The platform’s content management system stores a representation of the environment, together with a database of multimedia objects that can be associated with a location. The localization component fuses data from beacons …
Three-dimensional Cross-Platform Planning for Complex Spinal Procedures
2017
STUDY DESIGN A feasibility study. OBJECTIVE To develop a method based on the DICOM standard which transfers complex 3-dimensional (3D) trajectories and objects from external planning software to any navigation system for planning and intraoperative guidance of complex spinal procedures. SUMMARY OF BACKGROUND DATA There have been many reports about navigation systems with embedded planning solutions but only few on how to transfer planning data generated in external software. MATERIALS AND METHODS Patients computerized tomography and/or magnetic resonance volume data sets of the affected spinal segments were imported to Amira software, reconstructed to 3D images and fused with magnetic reson…
New Method of Microimages Generation for 3D Display
2018
In this paper, we propose a new method for the generation of microimages, which processes real 3D scenes captured with any method that permits the extraction of its depth information. The depth map of the scene, together with its color information, is used to create a point cloud. A set of elemental images of this point cloud is captured synthetically and from it the microimages are computed. The main feature of this method is that the reference plane of displayed images can be set at will, while the empty pixels are avoided. Another advantage of the method is that the center point of displayed images and also their scale and field of view can be set. To show the final results, a 3D InI dis…
Full-parallax 3D display from stereo-hybrid 3D camera system
2018
Abstract In this paper, we propose an innovative approach for the production of the microimages ready to display onto an integral-imaging monitor. Our main contribution is using a stereo-hybrid 3D camera system, which is used for picking up a 3D data pair and composing a denser point cloud. However, there is an intrinsic difficulty in the fact that hybrid sensors have dissimilarities and therefore should be equalized. Handled data facilitate to generating an integral image after projecting computationally the information through a virtual pinhole array. We illustrate this procedure with some imaging experiments that provide microimages with enhanced quality. After projection of such microim…