Reconstruction of Objects from their Projections Using Orthogonal Functions

1973 ◽  
Vol 31 ◽  
pp. 268-269
Author(s):  
Elrnar Zeitler
Keyword(s):  
Unit Area ◽  
Three Dimensional ◽  
One Dimension ◽  
Spatial Density ◽  
Dimensional Representation ◽  
Orthogonal Functions ◽  
Object A ◽  
Plane Normal ◽  
Dimensional Object ◽  
Spatial Density Distribution

Considering any finite three-dimensional object, a “projection” is here defined as a two-dimensional representation of the object's mass per unit area on a plane normal to a given projection axis, here taken as they-axis. Since the object can be seen as being built from parallel, thin slices, the relation between object structure and its projection can be reduced by one dimension. It is assumed that an electron microscope equipped with a tilting stage records the projectionWhere the object has a spatial density distribution p(r,ϕ) within a limiting radius taken to be unity, and the stage is tilted by an angle 9 with respect to the x-axis of the recording plane.

Three-Dimensional Object Surface Reconstruction Based on Camera Calibration and SIFT

2015 ◽  
Vol 719-720 ◽  
pp. 1191-1197 ◽  
Author(s):  
Jun Zhang ◽  
Long Ye ◽  
Qin Zhang ◽  
Jing Ling Wang
Keyword(s):  
3D Reconstruction ◽  
Camera Calibration ◽  
Image Matching ◽  
Three Dimensional ◽  
Target Object ◽  
Object A ◽  
Binocular Stereo Vision ◽  
Binocular Stereo ◽  
Dimensional Object

This paper is focused on camera calibration, image matching, both of which are the key issues in three-dimensional (3D) reconstruction. In terms of camera calibration firstly, we adopt the method based on the method proposed by Zhengyou Zhang. In addition to this, it is selective for us to deal with tangential distortion. In respect of image matching, we use the SIFT algorithm, which is invariant to image translation, scaling, rotation, and partially invariant to illumination changes and to affine or 3D projections. It performs well in the follow-up matching the corresponding points. Lastly, we perform 3D reconstruction of the surface of the target object. A Graphical User Interface is designed to help us to realize the key function of binocular stereo vision, with better visualization. Apparently, the entire GUI brings convenience to the follow-up work.

scholarly journals Reconstruction of Three-Dimensional Object from Two-Dimensional Images by Utilizing Distance Regularized Level Algorithm and Mesh Object Generation

2020 ◽  
Vol 17 (3) ◽  
pp. 0899
Author(s):  
Samera Shams Hussei ◽  
Sukaina Sh Altyar ◽  
Lubab Ahmed Tawfeeq ◽  
Eman S. Harba
Keyword(s):  
Good Accuracy ◽  
Low Cost ◽  
3D Structure ◽  
Three Dimensional ◽  
High Accuracy ◽  
Ease Of Use ◽  
3D Scanner ◽  
Object A ◽  
Human Organs ◽  
Dimensional Object

Three-dimensional (3D) reconstruction from images is a most beneficial method of object regeneration by using a photo-realistic way that can be used in many fields. For industrial fields, it can be used to visualize the cracks within alloys or walls. In medical fields, it has been used as 3D scanner to reconstruct some human organs such as internal nose for plastic surgery or to reconstruct ear canal for fabricating a hearing aid device, and others. These applications need high accuracy details and measurement that represent the main issue which should be taken in consideration, also the other issues are cost, movability, and ease of use which should be taken into consideration. This work has presented an approach for design and constructed a low-cost three-dimensional object scanner. We have proposed a 3D canal reconstruction system (ear or nose) based on using 2D images for reconstruction 3D object. A low-cost EndoScope with a proposed program based upon utilized the segmentation algorithm type “Distance Regularized Level” to segment active edges from images then generate mesh object in order to generate 3D structure for small canals or cracks. The results show good accuracy of the reconstructed object in both details and their measurements which are related to the success in the reconstruction of algorithm that yields good three-dimensional meshes object.  

scholarly journals Cognitive abilities of horses in terms of visual and olfactory perception

2017 ◽  
Vol 73 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Tomasz Próchniak ◽  
Iwona Rozempolska-Rucińska ◽  
Monika Petrykowska ◽  
Grzegorz Zięba ◽  
Brygida Ślaska ◽  
...  
Keyword(s):  
Visual Stimulus ◽  
Cognitive Abilities ◽  
Three Dimensional ◽  
Negative Reaction ◽  
Olfactory Perception ◽  
Two Dimensional ◽  
Object A ◽  
The One ◽  
Dimensional Object ◽  
The Right

The aim of the study was to assess the cognitive abilities of horses in recognizing humans by sight and smell. Two experiments were performed. In the first experiment, the behaviour of horses exposed to a visual stimulus (photographs of familiar and unfamiliar people) was observed. The second experiment examined their behaviour evoked by an olfactory stimulus. The following variables was assessed: the duration of approach to the object in seconds (s), interest in the object, a negative reaction, the duration of the observation of the object (s), the duration of looking with the left eye and the right eye (s), and other signs of interest, e.g. licking, grasping with lips, and touching the object. It was found that the horses were able to identify the human by transferring the identification of a three-dimensional object (a person that positively conditioned the horse) to a two-dimensional object (a photograph of that person’s face). It was also shown that the horses used the sense of smell in associating clothes with the person wearing them (the one who positively conditioned the horse). It was found that positively conditioned horses reacted more strongly to the smell of human clothes than to a photograph of the human.

scholarly journals Endodontic management of maxillary first molar with five canals: Report of a case aided with spiral computed tomography

2012 ◽  
Vol 59 (2) ◽  
pp. 104-109
Author(s):  
Gurudutt Nayak ◽  
Shashit Shetty ◽  
Hitesh Chopra ◽  
Abhinav Sharma
Keyword(s):  
Computed Tomography ◽  
Three Dimensional ◽  
Spiral Computed Tomography ◽  
Endodontic Treatment ◽  
Diagnostic Methods ◽  
Dimensional Representation ◽  
Spiral Computed ◽  
Gutta Percha ◽  
Ah Plus ◽  
Dimensional Object

Introduction. Maxillary first molars have shown substantial dissimilarity regarding their number of roots, canals and morphology. Most commonly, it has three roots and four canals, two mesiobuccal, one distobuccal and one palatal canal. The incidence of second mesiobuccal canal has been reported between 18% and 96.1% while the incidence of two distobuccal canals was found in 1.64% to 9.50% of cases. Periapical (PA) radiography has been commonly used to determine root canal anatomy even though it is two-dimensional representation of a three-dimensional object. Advanced diagnostic methods as spiral computed tomography (SCT) provide three-dimensional images useful to determine complex canal morphology. Case Report. A 31-year-old male patient was referred for endodontic treatment of the maxillary right first molar. Endodontic access cavity revealed two canal openings in each of the mesiobuccal and distobuccal roots and one canal in the palatal root later confirmed using the SCT and conventional PA radiography. The canals were instrumented using crown down technique with ProTaper NiTi rotary files. Obturation was performed using single gutta-percha cone and AH Plus paste. The patient remained asymptomatic during the regular checkups. Conclusion. Knowledge, detection and management of complex canal anatomy is of the foremost importance in endodontics since missed canals are one of well recognised reasons for endodontic treatment failure.

Revealing gross three-dimensional structure in the SEM

1987 ◽  
Vol 45 ◽  
pp. 656-657
Author(s):  
Sterling P. Newberry
Keyword(s):  
Freeze Drying ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Small Object ◽  
Final Solution ◽  
Dimensional Representation ◽  
X Ray ◽  
Three Dimensional Representation ◽  
Freeze Dried ◽  
Critical Point Drying

The beautiful three dimensional representation of small object surfaces by the SEM leads one to search for ways to open up the sample and look inside. Could this be the answer to a better microscopy for gross biological 3-D structure? We know from X-Ray microscope images that Freeze Drying and Critical Point Drying give promise of adequately preserving gross structure. Can we slice such preparations open for SEM inspection? In general these preparations crush more readily than they slice. Russell and Dagihlian got around the problem by “deembedding” a section before imaging. This some what defeats the advantages of direct dry preparation, thus we are reluctant to accept it as the final solution to our problem. Alternatively, consider fig 1 wherein a freeze dried onion root has a window cut in its surface by a micromanipulator during observation in the SEM.

scholarly journals Structured-light 3D scanning of exhibited historical clothing—a first-ever methodical trial and its results

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Jerzy Montusiewicz ◽  
Marek Miłosz ◽  
Jacek Kęsik ◽  
Kamil Żyła
Keyword(s):  
Cultural Heritage ◽  
Information Technologies ◽  
Structured Light ◽  
Three Dimensional ◽  
3D Models ◽  
3D Scanning ◽  
Dimensional Representation ◽  
3D Scanner ◽  
Three Dimensional Representation ◽  
3D Scanners

AbstractHistorical costumes are part of cultural heritage. Unlike architectural monuments, they are very fragile, which exacerbates the problems of their protection and popularisation. A big help in this can be the digitisation of their appearance, preferably using modern techniques of three-dimensional representation (3D). The article presents the results of the search for examples and methodologies of implementing 3D scanning of exhibited historical clothes as well as the attendant problems. From a review of scientific literature it turns out that so far practically no one in the world has made any methodical attempts at scanning historical clothes using structured-light 3D scanners (SLS) and developing an appropriate methodology. The vast majority of methods for creating 3D models of clothes used photogrammetry and 3D modelling software. Therefore, an innovative approach was proposed to the problem of creating 3D models of exhibited historical clothes through their digitalisation by means of a 3D scanner using structural light technology. A proposal for the methodology of this process and concrete examples of its implementation and results are presented. The problems related to the scanning of 3D historical clothes are also described, as well as a proposal how to solve them or minimise their impact. The implementation of the methodology is presented on the example of scanning elements of the Emir of Bukhara's costume (Uzbekistan) from the end of the nineteenth century, consisting of the gown, turban and shoes. Moreover, the way of using 3D models and information technologies to popularise cultural heritage in the space of digital resources is also discussed.

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