scholarly journals Projective Invariants from Multiple Images: A Direct and Linear Method

2016 ◽  
Vol 2016 ◽  
pp. 1-14
Author(s):  
Yuanbin Wang ◽  
Xingwei Wang ◽  
Bin Zhang
Keyword(s):  
Direct Method ◽  
Linear Method ◽  
Direct Methods ◽  
System Of Nonlinear Equations ◽  
Projective Reconstruction ◽  
Projective Structures ◽  
Indirect Methods ◽  
Projective Invariants ◽  
First Time ◽  
2D Images

The projective reconstruction of 3D structures from 2D images is a central problem in computer vision. Existing methods for this problem are usually nonlinear or indirect. In the previous direct methods, we usually have to solve a system of nonlinear equations. They are very complicated and hard to implement. The previous linear indirect methods are usually imprecise. This paper presents a linear and direct method to derive projective structures of 3D points from their 2D images. Algorithms to compute projective invariants from two images, three images, and four images are given. The method is clear, simple, and easy to implement. For the first time in the literature, we present explicit linear formulas to solve this problem.Mathematicacodes are provided to demonstrate the correctness of the formulas.

scholarly journals A Linear Method to Derive 3D Projective Invariants from 4 Uncalibrated Images

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
YuanBin Wang ◽  
XingWei Wang ◽  
Bin Zhang ◽  
Ying Wang
Keyword(s):  
Linear Method ◽  
Projective Reconstruction ◽  
Reconstruction Problem ◽  
Linear Transformations ◽  
Explicit Formulas ◽  
Projective Invariants ◽  
Projective Invariant ◽  
Uncalibrated Images ◽  
Bilinear Equations ◽  
2D Images

A well-known method proposed by Quan to compute projective invariants of 3D points uses six points in three 2D images. The method is nonlinear and complicated. It usually produces three possible solutions. It is noted previously that the problem can be solved directly and linearly using six points in five images. This paper presents a method to compute projective invariants of 3D points from four uncalibrated images directly. For a set of six 3D points in general position, we choose four of them as the reference basis and represent the other two points under this basis. It is known that the cross ratios of the coefficients of these representations are projective invariant. After a series of linear transformations, a system of four bilinear equations in the three unknown projective invariants is derived. Systems of nonlinear multivariable equations are usually hard to solve. We show that this form of equations can be solved linearly and uniquely. This finding is remarkable. It means that the natural configuration of the projective reconstruction problem might be six points and four images. The solutions are given in explicit formulas.

Direct and Indirect Methods for Calculating Thermal Emission From Layered Structures With Nonuniform Temperatures

2011 ◽  
Vol 133 (7) ◽  
Author(s):  
L. P. Wang ◽  
S. Basu ◽  
Z. M. Zhang
Keyword(s):  
Temperature Distribution ◽  
Thermal Emission ◽  
Local Density ◽  
Direct Method ◽  
Direct Methods ◽  
Layered Structures ◽  
Nonuniform Temperature ◽  
Indirect Methods ◽  
Nonuniform Temperature Distribution ◽  
Direct And Indirect Methods

The determination of emissivity of layered structures is critical in many applications, such as radiation thermometry, microelectronics, radiative cooling, and energy harvesting. Two different approaches, i.e., the “indirect” and “direct” methods, are commonly used for computing the emissivity of an object. For an opaque surface at a uniform temperature, the indirect method involves calculating the spectral directional-hemispherical reflectance to deduce the spectral directional emissivity based on Kirchhoff’s law. On the other hand, a few studies have used a combination of Maxwell’s equations with the fluctuation-dissipation theorem to directly calculate the emissivity. The present study aims at unifying the direct and indirect methods for calculating the far-field thermal emission from layered structures with a nonuniform temperature distribution. Formulations for both methods are given to illustrate the equivalence between the indirect and the direct methods. Thermal emission from an asymmetric Fabry–Pérot resonance cavity with a nonuniform temperature distribution is taken as an example to show how to predict the intensity, emissivity, and the brightness temperature. The local density of states, however, can only be calculated using the direct method.

Direct and Indirect Methods for Calculating Thermal Emission From Layered Structures With Nonuniform Temperatures

2010 ◽  
Author(s):  
L. P. Wang ◽  
S. Basu ◽  
Z. M. Zhang
Keyword(s):  
Temperature Distribution ◽  
Thermal Emission ◽  
Local Density ◽  
Direct Method ◽  
Direct Methods ◽  
Layered Structures ◽  
Nonuniform Temperature ◽  
Indirect Methods ◽  
Nonuniform Temperature Distribution ◽  
Direct And Indirect Methods

The determination of emissivity of layered structures is critical in many applications, such as radiation thermometry, microelectronics, radiative cooling, and energy harvesting. Two different approaches, i.e., the “indirect” and “direct” methods, are commonly used for computing the emissivity of an object. For an opaque surface at a uniform temperature, the indirect method involves calculating the spectral directional-hemispherical reflectance to deduce the spectral directional emissivity based on Kirchhoff’s law. On the other hand, a few studies have used a combination of Maxwell’s equations with the fluctuation-dissipation theorem to directly calculate the emissivity. The present study aims at unifying the direct and indirect methods for calculating thermal emission from layered structures with a nonuniform temperature distribution. Formulations for both methods are given to illustrate the equivalence between the indirect and the direct methods. Thermal emission from an asymmetric Fabry-Perot resonance cavity with a nonuniform temperature distribution is taken as an example to show how to predict the intensity, emissivity, and the brightness temperature. The local density of states, however, can only be calculated using the direct method.

scholarly journals Một phương pháp mới nâng cao độ tương phản ảnh màu theo hướng tiếp cận trực tiếp

2017 ◽  
pp. 59
Author(s):  
Nguyễn Văn Quyền ◽  
Nguyễn Tân Ân ◽  
Trần Thái Sơn ◽  
Ngô Hoàng Huy ◽  
Đặng Duy An
Keyword(s):  
Direct Method ◽  
Clustering Algorithms ◽  
Direct Methods ◽  
Color Images ◽  
Indirect Methods ◽  
Image Contrast Enhancement ◽  
Contrast Measure ◽  
Fcm Clustering ◽  
Different Color ◽  
Contrast Measurement

Image contrast enhancement techniques have two mainly methods: indirect method and direct method. While indirect methods only modify the histogram without defining any specific contrast measure, the direct methods establish a criterion of contrast measurement and enhance the image by improving the contrast measure. Among many direct methods, only the studies by Cheng and Xu modified the contrast at each point of grayscale image using a contrast measure [6, 7]. In this paper we propose a new method for enhancing the contrast of color images based on the direct method. The experimental results demonstrate that the combination of our proposed method with Fuzzy C_Mean (FCM) clustering algorithms performs well on different color images.

scholarly journals DIRECT METHOD AND INDIRECTNESS METHOD: COMMUNICATION STRATEGY IN CARTOON

2020 ◽  
Vol 2 (4) ◽  
pp. 01-12
Author(s):  
Rohaidah Mashudi ◽  
Norishamsawati Ishak ◽  
Hawa Rahmat ◽  
Faizuniza Mashhod ◽  
Isma Suhaila Ismail ◽  
...  
Keyword(s):  
Data Analysis ◽  
Language Use ◽  
Direct Method ◽  
Direct Methods ◽  
Study Data ◽  
Communication Strategy ◽  
Indirect Methods ◽  
The Press ◽  
Descriptive Approach ◽  
Direct And Indirect Methods

Cartoons are not only seen as a media channel to provide entertainment to the community. This is because cartoons play an important role as a very effective medium of information delivery to all groups. The message in the cartoon is conveyed either through the language use and illustrations or mere illustrations from a cartoonist. The display of illustrations with the language used in cartoons in the press indirectly brings current issues in various aspects. Even though these illustrations can help stimulate one's ideas and maturity in evaluating a message. The purpose of this study is to examine language use as a communication strategy in cartoons and describe the use of direct and indirect methods in cartoons. As such, the use of language as a communication strategy is examined based on the language use used in cartoons, namely the language use through direct methods and indirectness methods. The study was conducted qualitatively through a descriptive approach. Study data were taken and collected from cartoons or illustrations produced by Maro cartoonists in the Malaysia Kita column, Mingguan Malaysia. The illustration taken as study data is an illustration that gives an overview of the current situation of the country in Mingguan Malaysia every Sunday for the July and August issues in 2019 and August 2020. Data analysis is done through an approach that presented by Asmah Hj Omar through research on the language use through indirectness methods and the language use through direct methods. The results of this study can be observed that the cartoon in the newspaper clearly shows that there is an emphasis on these two methods as a communication strategy used through language use as a way to ensure that the message conveyed can be understood by all parties. Thus, language use through this indirectness method is the main choice in the delivery of storytelling through cartoons. The study of language on cartoon illustrations needs to be given a wider focus because there are still many vacancies that need to be examined.

scholarly journals Diurnal variation of leukocyte counts affects the indirect estimation of reference intervals

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Antje Torge ◽  
Rainer Haeckel ◽  
Mustafa Özcürümez ◽  
Alexander Krebs ◽  
Ralf Junker
Keyword(s):  
Diurnal Variation ◽  
Indirect Method ◽  
Venous Blood ◽  
Direct Methods ◽  
Reference Intervals ◽  
Indirect Methods ◽  
Indirect Estimation ◽  
Late Afternoon ◽  
Reference Limits ◽  
Leukocyte Counts

Abstract It has been observed that the estimation of reference intervals of leukocytes in whole venous blood leads to higher upper reference limits (uRLs) with indirect methods than has been reported in the literature determined by direct approaches. This phenomenon was reinvestigated with a newer, more advanced indirect method, and could be confirmed. Furthermore, a diurnal variation was observed with lower values during the morning and higher values in the late afternoon and at night. This observation can explain why indirect approaches using samples collected during 24 h lead to higher uRLs than direct methods applied on samples collected presumably in the morning.

scholarly journals The Preference of Direct or Indirect Methods in Preparing the Statement of Cash Flows in Decision Making: An Academic Perspective

2016 ◽  
Vol 8 (2) ◽  
pp. 206
Author(s):  
Abdullah, S. Hardan ◽  
Majed, A. Qabajeh ◽  
Aymen, M. Alshanti
Keyword(s):  
Decision Making ◽  
Indirect Method ◽  
Direct Method ◽  
Cash Flows ◽  
Decision Makers ◽  
Academic Rank ◽  
Indirect Methods ◽  
Statement Of Cash Flows ◽  
Qualitative Characteristics ◽  
Academic Sector

Two methods are used when reporting cash flows from operating activities: the direct method or the indirect method, both are acceptable from IAS with a preference of direct method. Thus, this paper examines which method of reporting the statement of cash flows provides useful information the decision makers rely on for decision making purposes. To achieve this aim, participants were selected from academic sector represented by universities professors. The study is based on the conceptual framework: qualitative characteristics of accounting information. To be useful, information must be relevant and represents faithfully what it claims to represent. In order to distinguish more useful financial information from those less useful, enhancing qualitative characteristics were examined. Results show that academic professors provide support for direct method of reporting cash flows over indirect method. The study sought to determine the effect of academic rank on these results. Evidence reveals that full and associate professors endorsed the preference of direct method more than assistant professors and lecturers. These results recommend the legislative bodies and entities to adopt the direct method in preparation the statement of cash flows.

scholarly journals Lectin-binding histochemistry of non-decalcified growth plate cartilage: a postembedment method for light microscopy of epon-embedded tissue.

1984 ◽  
Vol 32 (6) ◽  
pp. 593-607 ◽  
Author(s):  
C E Farnum ◽  
N J Wilsman
Keyword(s):  
Growth Plate ◽  
Morphological Analysis ◽  
Lectin Binding ◽  
Direct Methods ◽  
Miniature Swine ◽  
Double Labeling ◽  
Indirect Methods ◽  
Growth Plate Cartilage ◽  
Disease States ◽  
Intracellular Binding

A postembedment method for the localization of lectin-binding glycoconjugates was developed using Epon-embedded growth plate cartilage from Yucatan miniature swine. By testing a variety of etching, blocking, and incubation procedures, a standard protocol was developed for 1 micron thick sections that allowed visualization of both intracellular and extracellular glycoconjugates with affinity for wheat germ agglutinin and concanavalin A. Both fluorescent and peroxidase techniques were used, and comparisons were made between direct methods and indirect methods using the biotin-avidin bridging system. Differential extracellular lectin binding allowed visualization of interterritorial , territorial, and pericellular matrices. Double labeling experiments showed the precision with which intracellular binding could be localized to specific cytoplasmic compartments, with resolution of binding to the Golgi apparatus, endoplasmic reticulum, and nuclear membrane at the light microscopic level. This method allows the localization of both intracellular and extracellular lectin-binding glycoconjugates using fixation and embedment procedures that are compatible with simultaneous ultrastructural analysis. As such it should have applicability both to the morphological analysis of growth plate organization during normal endochondral ossification, as well as to the diagnostic pathology of matrix abnormalities in disease states of growing cartilage.

scholarly journals Jurnal Al-Maraji' Volume 1. Nomor 1. Juni 2017

2018 ◽  
Author(s):  
PUJIA UNISMUH MAKASSAR
Keyword(s):  
Foreign Language ◽  
Mother Tongue ◽  
Language Teaching ◽  
Direct Method ◽  
Point Method ◽  
Learning Science ◽  
Teaching Language ◽  
First Time ◽  
Science Subject ◽  
The Way

Direct means straight to the point. Direct method or straight to the point method is the way in presenting Arabic where the teacher directly uses the language ( Arabic) as the language in giving instruction , without using students’ mother tongue . If there is a word is difficult to understand by the students, teachers can interpret that word by using props, demonstrating, describing and etc. This method is based on the understanding that teaching foreign language subject is not the same as teaching the science subject. If in the Learning science, the students are required to memorize certain formulas, think and remember, in language teaching, students or pupil are trained to practice directly spelling certain words or sentences. It is same when we consider a mother in teaching language to her childrens, she practices the language by herself directly , lead her child to pronounce the word by -word, sentence by-sentence, and her children will repeat what she spell in funny way. In principle, Direct method is really important in teaching Arabic, because through this method students can practice their speaking skills directly without using their mother tongue (the language of their scope). Although in the first time it seems difficult for students to duplicate it, but this method finally so interesting for them .

scholarly journals Metode Langsung (Al-Tarīqah Al-Mubāsyarah) dan Strategi Pembelajarannya

2020 ◽  
Vol 8 (2) ◽  
pp. 161
Author(s):  
Sitti Aisyah Chalik
Keyword(s):  
Foreign Language ◽  
Mother Tongue ◽  
Language Teaching ◽  
Direct Method ◽  
Point Method ◽  
Learning Science ◽  
Teaching Language ◽  
First Time ◽  
Science Subject ◽  
The Way

Direct means straight to the point. Direct method or straight to the point method is the way in presenting Arabic where the teacher directly uses the language ( Arabic) as the language in giving instruction , without using students‟ mother tongue . If there is a word is difficult to understand by the students, teachers can interpret that word by using props, demonstrating, describing and etc. This method is based on the understanding that teaching foreign language subject is not the same as teaching the science subject. If in the Learning science, the students are required to memorize certain formulas, think and remember, in language teaching, students or pupil are trained to practice directly spelling certain words or sentences. It is same when we consider a mother in teaching language to her childrens, she practices the language by herself directly , lead her child to pronounce the word by -word, sentence by-sentence, and her children will repeat what she spell in funny way. In principle, Direct method is really important in teaching Arabic, because through this method students can practice their speaking skills directly without using their mother tongue (the language of their scope). Although in the first time it seems difficult for students to duplicate it, but this method finally so interesting for them. 

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