Chain Code Algorithm in Deriving T–Junction and Region of a Freehand Sketch

2012 ◽  
Author(s):  
Habibollah Haron ◽  
Siti Mariyam Shamsuddin ◽  
Dzulkifli Mohamed
Keyword(s):  
Closed Loop ◽  
Line Drawing ◽  
Three Dimensional ◽  
Chain Code ◽  
Freehand Sketch ◽  
Code Algorithm ◽  
Picture Description ◽  
Loop Chain ◽  
Description Languages ◽  
Line Drawing Interpretation

Perwakilan kod rantai ialah salah satu daripada Bahasa Penghuraian Gambar yang digunakan untuk mewakili garisan. Kertas kerja ini menfokuskan kepada terjemahan lukisan garisan dengan menerapkan algoritma kod rantaai dalam mendapatkan dua entiti geometri, iaitu simpang–T dan kawasan, bagi lakaran lukisan garisan dua dimensi. Algoritma kod rantai tertutup ini mengandaikan bahawa lakaran mewakili objek padu tiga dimensi. Algoritma ini ialah berasaskan kod rantai Freeman 8–kaitan dalam tetingkap 3×3. Terdapat dua faktor yang menentukan kejayaan algoritma ini. Pertama ialah arah penjelajahan sama ada ikut jam atau lawan jam. Kedua ialah lokasi permulaan bagi penjelajahan dalam tetingkap 3×3 tersebut. Kertas kerja ini menerangkan faktor-faktor ini dan aplikasi mereka dalam mendapatkan entiti geometri tersebut. Perbincangan ini dibantu oleh contoh lakaran objek blok–L untuk memudahkan pemahaman terhadap algoritma. Kertas kerja ini diakhiri dengan kesimpulan dan cadangan pembaikan. Kata kunci: Terjemahan lukisan garisan, kod rantaian, objek blok-L, Bahasa Penghuraian Gambar Chain code scheme is one of the Picture Description Languages used to represent lines. This paper focuses on the line drawing interpretation by utilising closed loop chain code algorithm as a tool in deriving two geometric entities, i.e. T–junction and region, of a two–dimensional line drawing sketch. The closed loop chain code algorithm assumes that the sketch represents a three–dimensional solid object. The algorithm is based on 8–connected 3×3 windows of Freeman chain code. Two factors determine the success of the algorithm. The first factor is the direction of traverses either clockwise or anti–clockwise. The other is the start location of the 3×3 window traverse. This paper explains these factors and their applications in deriving the geometric entities. The discussion is supported with an example of L–block object for clarification in the presentation of the algorithm. This paper is concluded with conclusion and future works. Keywords: Line drawing interpretation, chain code, L-block object, Picture Description Languages

Extraction of Junctions, Lines and Regions of Irregular Line Drawing: The Chain Code Processing Algorithm

2012 ◽  
Author(s):  
Habibollah Haron ◽  
Dzulkifli Mohamed ◽  
Siti Mariyam Hj. Shamsuddin
Keyword(s):  
Feature Extraction ◽  
Key Words ◽  
Line Drawing ◽  
Engineering Product ◽  
Chain Code ◽  
Thinning Algorithm ◽  
Test Input ◽  
Code Algorithm ◽  
Regular Line ◽  
Thinning Process

Peringkat konsepsualisasi dalam kitar hayat reka bentuk produk kejuruteraan merupakan proses menterjemahkan idea jurutera ke atas sehelai kertas. Menggunakan sebatang pensil dan sehelai kertas, bentuk produk yang diinginkan akan dilakar. Lakaran seterusnya akan dikemaskinikan dengan menambah dimensi yang lebih tepat beserta pandangan-pandangan tambahan bagi menunjukkan kawasan terlindung. Kertas kerja ini membincangkan proses-proses yang terlibat dalam menterjemahkan lakaran berupa lukisan garisan tak sekata kepada lukisan sekata yang kemas. Proses ini juga turut menghasilkan tiga entiti penting iaitu simpang, garisan dan kawasan. Algoritma kod rantaian digunakan bagi mendapatkan entiti ini. Kertas kerja ini juga menerangkan proses penipisan yang terlibat sebelum algoritma kod rantaian dilaksanakan. Andaian-andaian, beberapa definisi penting dan kaedah memindahturun fail imej juga dipersembahkan. Kertas kerja ini diakhiri dengan beberapa lakaran input, kesimpulan dan cadangan pembaikan. Kata kunci: Terjemahan lukisan garisan; kod rantaian; pengestrakkan ciri; algoritma penipisan Conceptualization stage in designing engineering product is a process of translating engineer´s idea onto a sheet of paper. The product is always sketched on a sheet of paper using pencil. The sketch is tidied up by adding accurate dimension, and complete view of hidden part. This paper discusses part of the process involved in translating the sketch or irregular line drawing into a tidy or regular line drawing, that yield three important entities namely junction, line and region. The chain code algorithm is used to find these entities. The paper also explains explicit thinning process involved before the chain code methodology. Assumptions, important definitions and method of loading image file are also presented. The paper is concluded with several test input sketches, conclusion and future works. Key words: Line drawing; interpretation; chain code; feature extraction; thinning algorithm

Hand line drawing interpretation as three-dimensional objects

1993 ◽  
Vol 32 (1-2) ◽  
pp. 91-110 ◽  
Author(s):  
E Martí ◽  
J Regincós ◽  
J López-Krahe ◽  
J.J Villanueva
Keyword(s):  
Line Drawing ◽  
Three Dimensional ◽  
Three Dimensional Objects ◽  
Line Drawing Interpretation

scholarly journals Automatic Detection of Pulmonary Nodules using Three-dimensional Chain Coding and Optimized Random Forest

2020 ◽  
Vol 10 (7) ◽  
pp. 2346 ◽  
Author(s):  
May Phu Paing ◽  
Kazuhiko Hamamoto ◽  
Supan Tungjitkusolmun ◽  
Sarinporn Visitsattapongse ◽  
Chuchart Pintavirooj
Keyword(s):  
Random Forest ◽  
Three Dimensional ◽  
Pulmonary Nodules ◽  
Region Growing ◽  
Favorable Result ◽  
Dimensional Chain ◽  
Chain Code ◽  
Seeded Region Growing ◽  
Chain Coding ◽  
Diagnosis Of Lung Cancer

The detection of pulmonary nodules on computed tomography scans provides a clue for the early diagnosis of lung cancer. Manual detection mandates a heavy radiological workload as it identifies nodules slice-by-slice. This paper presents a fully automated nodule detection with three significant contributions. First, an automated seeded region growing is designed to segment the lung regions from the tomography scans. Second, a three-dimensional chain code algorithm is implemented to refine the border of the segmented lungs. Lastly, nodules inside the lungs are detected using an optimized random forest classifier. The experiments for our proposed detection are conducted using 888 scans from a public dataset, and achieves a favorable result of 93.11% accuracy, 94.86% sensitivity, and 91.37% specificity, with only 0.0863 false positives per exam.

Parameterization of Three-Dimensional Rigid Body Guidance Incorporating Planar Gear Connections in a Spatial Closed-Loop Mechanism With Parallel Consecutive Axes

2008 ◽  
Author(s):  
Javier Rolda´n Mckinley ◽  
Carl Crane ◽  
David B. Dooner
Keyword(s):  
Computer Animation ◽  
Closed Loop ◽  
Three Dimensional ◽  
Motion Generation ◽  
Repetitive Motion ◽  
End Effector ◽  
Spatial Mechanism ◽  
Joint Axis ◽  
Position And Orientation ◽  
Six Degree Of Freedom

This paper introduces a reconfigurable closed-loop spatial mechanism that can be applied to repetitive motion tasks. The concept is to incorporate five pairs of non-circular gears into a six degree-of–freedom closed-loop spatial chain. The gear pairs are designed based on given mechanism parameters and a user defined motion specification of a coupler link of the mechanism. It is shown in the paper that planar gear pairs can be used if the spatial closed-loop chain is comprised of six pairs of parallel joint axes, i.e. the first joint axis is parallel to the second, the third is parallel to the fourth, ..., and the eleventh is parallel to the twelfth. This paper presents the synthesis of the gear pairs that satisfy a specified three-dimensional position and orientation need. Numerical approximations were used in the synthesis the non-circular gear pairs by introducing an auxiliary monotonic parameter associated to each end-effector position to parameterize the motion needs. The findings are supported by a computer animation. No previous known literature incorporates planar non-circular gears to fulfill spatial motion generation needs.

scholarly journals Flexible Die Design and Springback Compensation Based on Modified Displacement Adjustment Method

2014 ◽  
Vol 6 ◽  
pp. 131253 ◽  
Author(s):  
Young-Ho Seo ◽  
Ji-Woo Park ◽  
Woo-Jin Song ◽  
Beom-Soo Kang ◽  
Jeong Kim
Keyword(s):  
Closed Loop ◽  
Three Dimensional ◽  
Loop System ◽  
Die Design ◽  
Manufacturing Cost ◽  
Closed Loop System ◽  
Forming Process ◽  
Element Analysis ◽  
Springback Compensation ◽  
Flexible Die

Springback in metal forming process often results in undesirable shape changes in formed parts and leads to deterioration in product quality. Even though springback can be predicted and compensated for through the theories or methodologies established thus far, an increase in manufacturing cost accompanied by a change in die shape is inevitable. In the present paper, it is suggested that the cost accompanied with springback compensation can be minimized while allowing the processing of various three-dimensional curved surfaces by using a flexible die composed of multiple punches. With the die being very flexible, the iterative trial-and-error method can be readily applied to compensate for the springback. Thus, repeated designing and redesigning of solid or matched dies can be avoided, effectively saving considerable time. Only some adjustments of punch height are required. Detailed designs of the flexible die as well as two core algorithms to control the respective punch heights are described in this paper. In addition, a closed-loop system for the springback compensation using the flexible die is proposed. The amount of springback was simulated by a finite element analysis and the modified displacement adjustment (DA) method as the springback compensation model was used in the closed-loop system. This system was applied to a two-dimensional quadratic shape problem, and its robustness was verified by an experiment.

Cognitive Issues in Virtual Reality

1995 ◽  
Author(s):  
Christopher D. Wickens ◽  
Polly Baker
Keyword(s):  
Virtual Reality ◽  
Closed Loop ◽  
Three Dimensional ◽  
Open Loop ◽  
Frame Of Reference ◽  
Realistic View ◽  
Static Images ◽  
Sense Of Reality ◽  
Inside Out

Virtual reality involves the creation of multisensory experience of an environment (its space and events) through artificial, electronic means; but that environment incorporates a sufficient number of features of the non-artificial world that it is experienced as “reality.” The cognitive issues of virtual reality are those that are involved in knowing and understanding about the virtual environment (cognitive: to perceive and to know). The knowledge we are concerned with in this chapter is both short term (Where am I in the environment? What do I see? Where do I go and how do I get there?), and long term (What can and do I learn about the environment as I see and explore it?). Given the recent interest in virtual reality as a concept (Rheingold, 1991; Wexelblat, 1993; Durlach and Mavor, 1994), it is important to consider that virtual reality is not, in fact, a unified thing, but can be broken down into a set of five features, any one of which can be present or absent to create a greater sense of reality. These features consist of the following five points. 1. Three-dimensional (perspective and/or stereoscopic) viewing vs. two-dimensional planar viewing. (Sedgwick, 1986; Wickens et al., 1989). Thus, the geography student who views a 3D representation of the environment has a more realistic view than one who views a 2D contour map. 2. Dynamic vs. static display. A video or movie is more real than a series of static images of the same material. 3. Closed-loop (interactive or learner-centered) vs. open-loop interaction. A more realistic closed-loop mode is one in which the learner has control over what aspect of the learning “world” is viewed or visited. That is, the learner is an active navigator as well as an observer. 4. Inside-out (ego-referenced) vs. outside-in (world-referenced) frame-of-reference. The more realistic inside-out frame-of-reference is one in which the image of the world on the display is viewed from the perspective of the point of ego-reference of the user (that point which is being manipulated by the control). This is often characterized as the property of “immersion.” Thus, the explorer of a virtual undersea environment will view that world from a perspective akin to that of a camera placed on the explorer’s head;

scholarly journals Fabrication of Micro-Punch Array by Plasma Printing for Micro-Embossing into Copper Substrates

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2640
Author(s):  
Tomomi Shiratori ◽  
Tatsuhiko Aizawa ◽  
Yasuo Saito ◽  
Kuniaki Dohda
Keyword(s):  
Stainless Steel ◽  
Closed Loop ◽  
Plasma Nitriding ◽  
Testing Machine ◽  
Three Dimensional ◽  
Copper Plate ◽  
Two Dimensional ◽  
Sand Blasting ◽  
Geometric Configurations ◽  
Micro Pattern

Copper substrates were wrought to have micro-grooves for packaging by micro-stamping with use of a AISI316 stainless steel micro-punch array. The micro-texture of this arrayed punch was first tailored and compiled into CAD data. A screen film was prepared to have the tailored micro-pattern in correspondence to the CAD data. A negative pattern to this screen was printed directly onto the AISI316 die substrate. This substrate was plasma nitrided at 673 K for 14.4 ks. The unprinted die surfaces were selectively nitrogen super-saturated to have sufficiently high corrosion toughness and hardness; other surfaces were masked by the prints. The two-dimensional micro-pattern on the screen was transformed into a three-dimensional nitrogen supersaturated micro-texture embedded in the AISI316 die. The printed surfaces were selectively sand-blasted to fabricate the micro-textured punch array for micro-embossing. A uniaxial compression testing machine was utilized to describe the micro-embossing behavior in copper substrates and to investigate how the micro-texture on the die was transcribed to the copper. The micro-punch array in this study consisted of three closed loop heads with a width of 75 µm and a height of 120 µm after plasma nitriding and sand-blasting. Since the nitrogen supersaturated heads had sufficient hardness against the blasting media, the printed parts of AISI316 die were removed. The micro-embossing process was described by comparison of the geometric configurations between the multi-punch array and the embossed copper plate.

Performance Characteristics of Two- and Three-Dimensional Impellers in Centrifugal Compressors

1988 ◽  
Vol 110 (1) ◽  
pp. 110-114 ◽  
Author(s):  
H. Harada
Keyword(s):  
Centrifugal Compressor ◽  
Closed Loop ◽  
Three Dimensional ◽  
Test Stand ◽  
Performance Characteristics ◽  
Working Fluid ◽  
Angle Distribution ◽  
Blade Angle ◽  
Operating Range ◽  
Overall Performance

The overall performance of two- and three-dimensional impellers of a centrifugal compressor were tested and compared. A closed-loop test stand with Freon gas as the working fluid was employed for the experiments. The inlet and outlet velocity distributions of all impellers were measured using three-hole cobra probes. As a result, it has been revealed that three-dimensional impeller in terms of efficiency, head coefficient, and operating range. Further, it has also been clarified that the impeller slip factor is affected by blade angle distribution.

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