Line Drawing Algorithm Research Articles

Study of image reconstruction method for 2D gamma scan technique by anti-aliasing line "Xiaolin Wu" algorithm combined with simultaneous algebraic reconstruction algorithms and testing on MCNP simulation data

Gamma scanning technique is known to be an effective method for survey the condition of distillation columns in petrochemical refineries and has been widely applied. The result of the gamma scanning is a 1-dimensional graph showing the transmittance counts according to the height of the column. To illuminate the important phenomena occurring on the tray such as foaming; flooding; weeping due to valve failure on the tray needs experienced people and the interpretation results are still quite qualitative. The method of 2-D gamma scanning and reconstruction (2D Tomography), which has just appeared in the world in recent years, is considered as a potential method to help detect the above phenomena. This report presents the two-dimensional gamma scanning configuration, mathematical calculation and noise processing methods by using the combination of Xiaolin Wu’s line drawing algorithm with simultaneous algebraic reconstruction algorithm (SART) based on data from Monte Carlo simulation.

Factual to Virtual Visualization

The purpose of this study is to explore the formation of image output in computer system from the user input information. The study seeks to answer the research question How does the image displayed on the computer screen and how appearance of image changed? The goal is to analyze transformation of real world picture to computerized output image in a very simple method by explaining all major components involved in this process in detail with diagrams. Further by using some mathematical concepts algorithms are derived and implemented to transform the images to change their shapes, sizes etc As there is a very near context between computer science and mathematics. Systems works completely based on the algorithms written to perform the particular task, algorithms are designed based on the mathematical concepts and are implemented by the programming languages in computer. Paper concentrates on the graphic capabilities and potentials of the digital computer. It presents an abstract idea of system that, how computer works internally to create and represent the simple graphical elements and images which human can see and understand. Paper presents all the components and related concepts with suitable examples from input information to graphical output produced by computer. After by getting the concept of image formation the next step is to know that how transformation of image takes place by changing original image. This paper illustrates four types of transformations with example translation, rotation, scaling, and shearing. Paper explores about display devices, different types of display methods, programming tools and finally drawing of a simple line in computer screen using a simple line drawing algorithm. Further it elaborates the concept of pixels, resolution, aspect ratio, persistency, different types of transformations etc.,

Clock Skew Compensation Algorithm Immune to Floating-Point Precision Loss

We propose a novel clock skew compensation algorithm based on Bresenham's line drawing algorithm. The proposed algorithm can avoid the effect of limited floating-point precision (e.g., 32-bit single precision) on clock skew compensation and thereby provide high-precision time synchronization even with resource-constrained sensor nodes in wireless sensor networks.

Bresenham's Line and Circle Drawing Algorithm using FPGA

In Bresenham's line drawing algorithm, the points of an n-dimensional raster that have to be selected are determined forming a close approximation to a straight line existed between two points. It is widely used for drawing line primitives in a bitmap image (for example: on a computer screen), since only integer addition, subtraction and bit shifting are used. These three operations are cheap concerning standard computer architectures. In addition, it is an incremental error algorithm. It is among the oldest algorithms that have been developed in computer graphics. An extension to the original algorithm may lead to draw circles. This research deals with the Bresenham’s line and circle drawing algorithm based on FPGA hardware platform. The shapes on the VGA screen are displayed via internal VGA port that is built in the device.

An Efficient 2.5D Shadow Detection Algorithm for Urban Planning and Design Using a Tensor Based Approach

Urbanization is leading us to a more chaotic state where healthy living becomes a prime concern. The high-rise buildings influence the urban setting with a high shadow rate on surroundings that can have no positive impact on the general neighborhood. Nevertheless, shadows are the main factor of defeatist virtual settings, they are expensive to render in real-time. This paper investigates how the amount of sunlight varies by season and how seasons can indicate the time of year to understand how shadows vary in length at different times of the day and how they change over the seasons. We propose a novel efficient (fast and scalable) algorithm to calculate a 2.5D cast-shadow map from a given LiDAR-derived Digital Surface Model (DSM). We present a proof-of-concept demonstration to examine the technical practicability of the introduced algorithm. Tensor-based techniques such as singular value decomposition, tensor unfolding are examined and deployed to represent the multidimensional data. The proposed method exploits horizon mapping ideas and extends the method to a modern graphics algorithm (Bresenham’s line drawing algorithm) to account for the DSM’s underlying surface geometry. A proof-of-concept is developed utilizing Python’s TensorFlow library, exploring data flow graphs and the tensor data structure. The heavy computer graphics algorithm used in this paper is parallelized using PySpark. Results explicate significant enhancements in overall performance while preserving accuracy at negligible variations.

Modeling the Line: Bresenham’s Algorithm, 1962–87

This paper follows the proliferation of the “line-drawing algorithm,” a method for encoding lines into digital media that saw widespread application in early interactive computing. The algorithm reveals a tightly linked complex of graphical technologies which integrated disparate hardware and software into continuous, real-time operation. Generated by this algorithm, the rasterized line offered an interactive form of graphic production, one categorically distinct from the inscribed line of orthographic representation. It transformed geometry into a computable entity, reproduced the line in an array of display technologies, and standardized its usage through the practices of computer graphics programming. As an automated method that produced lines from data manipulated by a user, the algorithm illuminates a shift in the work of graphic representation from drawing to modeling. This change is considered against discourses that posit line drawing as integral to an architectural notion of representation, examining the capacity of the algorithmic line to mask historical discontinuities and suggesting that drawing and line, rather than denoting stable disciplinary categories, are constantly constructed within broader technological regimes.

Design of Electric Power Line Drawing Algorithm

Abstract At present, the drawing of power lines is still in the state of semi-manual design, mainly completed by AutoCAD, which not only consumes human resources, but also has low efficiency. Therefore, this paper designs an automatic drawing software for power lines. It integrates drawing and data management. Based on the basic information of power lines, this software imports and automatically converts the basic power data (latitude and longitude data) containing GPS/BeidDou positioning information into the distance, direction, angle and other information of poles and cables. Then, it realizes the function of automatically drawing the power line graph according to the scale by multiple tree traversal algorithm. This software is easy to operate and reliable, and has achieved good results in practice.

Hardware/software co-design for a parallel three-dimensional bresenham’s algorithm

<p>Line plotting is the one of the basic operations in the scan conversion. Bresenham’s line drawing algorithm is an efficient and high popular algorithm utilized for this purpose. This algorithm starts from one end-point of the line to the other end-point by calculating one point at each step. As a result, the calculation time for all the points depends on the length of the line thereby the number of the total points presented. In this paper, we developed an approach to speed up the Bresenham algorithm by partitioning each line into number of segments, find the points belong to those segments and drawing them simultaneously to formulate the main line. As a result, the higher number of segments generated, the faster the points are calculated. By employing 32 cores in the Field Programmable Gate Array, a line of length 992 points is formulated in 0.31μs only. The complete system is implemented using Zybo board that contains the Xilinx Zynq-7000 chip (Z-7010).<em></em></p>

Machine Learning is Line Drawing Algorithm

Machine Learning is Line Drawing Algorithm

Brain Tumor Boundary Segmentation of MR Imaging using Spatial Domain Image Processing

Extracting information for medical purposes from magnetic resonance imaging is critically important for diagnostic and treatment plans. In this paper, a simple algorithm for tumor segmentation of Magnetic resonance imaging (MRI) is introduced. The novelty incorporates, preserving fine details of the input image while detecting the boundary accurately. Tumor segmentation is carried out by set of pre processing steps followed by morphological operations. Rough contour of the tumor is localized to reduce the search space for the boundary. Line drawing algorithm in cooperated with pixel selection criteria is used to detect the accurate boundary. The algorithm is evaluated in terms of the performance and accuracy with radiologist labelled ground truth MRI scans. Simulation results show that the proposed algorithm provides better identification with above 95% of accuracy, for clearly distinguishable tumors in relation to conventional contour detection methods.

GPU加速的表意式体模型线绘制算法

Existing line drawing algorithms for volumes extract feature lines by tracing randomly selected seeds, which is known to have severe temporal coherence problems. We propose a GPU-based line drawing algorithm framework for volume data. The algorithm extracts all feature lines in every frame, eliminating the discontinuity artifacts in successive frames. Firstly, we propose a parallel algorithm to extract feature line segments in each cell in the geometry shader. To determine the visibility of feature lines, we use splatting to render a depth map for each frame, achieving much higher performance than the ray-casting method adopted in previous approaches. Correct visibility is obtained by using adaptive depth offsets. To store the large volume data in the high-speed video memory, we propose efficient data pruning and encoding schemes, which remarkably reduce the memory consumption and bandwidth, while maintaining the line drawing quality. Experimental results show that, our method can render high quality line drawings with temporal coherence, with a rendering speed that is an order of magnitude faster than previous CPU-based methods using seed-and-traversal.

Line Integral Convolution for Real‐Time Illustration of Molecular Surface Shape and Salient Regions

AbstractWe present a novel line drawing algorithm that illustrates surfaces in real‐time to convey their shape. We use line integral convolution (LIC) and employ ambient occlusion for illustrative surface rendering. Furthermore, our method depicts salient regions based on the illumination gradient. Our method works on animated surfaces in a frame‐coherent manner. Therefore, it yields an illustrative representation of time‐dependent surfaces as no preprocessing step is needed. In this paper, the method is used to highlight the structure of molecular surfaces and to illustrate important surface features like cavities, channels, and pockets. The benefit of our method was evaluated with domain experts. We also demonstrate the applicability of our method to medical visualization.

Estimation of Tilt in Characters and Correction for better Readability by OCR Systems

existing Optical Character Readers (OCRs) are capable of reading linear form text and have limitations to read artistic and non-linear form text. The tilt in characters contributes a major share in affecting the efficiency of the recognition algorithms. This paper presents a technique to estimate and correct the vertical tilt in printed characters of English in order to make an OCR to read the text more efficiently. The input characters are assumed to be segmented from the document image and free from noise. Initially, the direction of tilt of the characters is detected using a heuristically constructed knowledgebase. Next, the inclination of the character to its base is estimated using line drawing algorithm. Finally, the estimated tilt is corrected through rotation in counter direction of the tilt. The method has been tested with sufficient samples and readability analysis is performed with an OCR. Experimental results show an average improvement in readability by OCR from 20% before tilt correction to 82% after the tilt correction. Keywordsinear text, Artistic text, Tilt in characters, Tilt correction, OCR.

Intelligent Custom Block Generation

The current density of integration circuits, yields extremely complex Systems-on-a-Chip (SoCs) that take a long time to design and develop and thus, many times, they miss the market window for these products. This has motivated intensive research on High-level Synthesis (HLS) methodologies, so that such complex and custom systems are rapidly designed and prototyped. The contribution of this work is a formal and intelligent HLS synthesis and rapid verification methodology with custom options, which re-uses and incorporates the generation of predesigned custom hardware functional units, from abstract behavioural ADA code. The usability of the proposed methodology is confirmed with a number of HLS benchmarks including a hierarchical RSA crypto-processor design and a line-drawing algorithm from computer graphics.

POLYGONAL APPROXIMATION OF DIGITAL CURVE BASED ON REVERSE ENGINEERING CONCEPT

This paper applies reverse engineering on the Bresenham's line drawing algorithm [J. E. Bresenham, IBM System Journal, 4, 106–111 (1965)] for polygonal approximation of digital curve. The proposed method has a number of features, namely, it is sequential and runs in linear time, produces symmetric approximation from symmetric digital curve, is an automatic algorithm and the approximating polygon has the least non-zero approximation error as compared to other algorithms.

Streamlines for Illustrative Real‐Time Rendering

AbstractLine drawing techniques are important methods to illustrate shapes. Existing feature line methods, e.g., suggestive contours, apparent ridges, or photic extremum lines, solely determine salient regions and illustrate them with separate lines. Hatching methods convey the shape by drawing a wealth of lines on the whole surface. Both approaches are often not sufficient for a faithful visualization of organic surface models, e.g., in biology or medicine. In this paper, we present a novel object‐space line drawing algorithm that conveys the shape of such surface models in real‐time. Our approach employs contour‐ and feature‐based illustrative streamlines to convey surface shape (ConFIS). For every triangle, precise streamlines are calculated on the surface with a given curvature vector field. Salient regions are detected by determining maxima and minima of a scalar field. Compared with existing feature lines and hatching methods, ConFIS uses the advantages of both categories in an effective and flexible manner. We demonstrate this with different anatomical and artificial surface models. In addition, we conducted a qualitative evaluation of our technique to compare our results with exemplary feature line and hatching methods.

Whisper: Tracing the Spatiotemporal Process of Information Diffusion in Real Time.

When and where is an idea dispersed? Social media, like Twitter, has been increasingly used for exchanging information, opinions and emotions about events that are happening across the world. Here we propose a novel visualization design, "Whisper", for tracing the process of information diffusion in social media in real time. Our design highlights three major characteristics of diffusion processes in social media: the temporal trend, social-spatial extent, and community response of a topic of interest. Such social, spatiotemporal processes are conveyed based on a sunflower metaphor whose seeds are often dispersed far away. In Whisper, we summarize the collective responses of communities on a given topic based on how tweets were retweeted by groups of users, through representing the sentiments extracted from the tweets, and tracing the pathways of retweets on a spatial hierarchical layout. We use an efficient flux line-drawing algorithm to trace multiple pathways so the temporal and spatial patterns can be identified even for a bursty event. A focused diffusion series highlights key roles such as opinion leaders in the diffusion process. We demonstrate how our design facilitates the understanding of when and where a piece of information is dispersed and what are the social responses of the crowd, for large-scale events including political campaigns and natural disasters. Initial feedback from domain experts suggests promising use for today's information consumption and dispersion in the wild.

Line drawing algorithm based on pixel chain

In order to increase the efficiency of the line drawing algorithm when the slope of the line is greater than 0.5,a line drawing algorithm based on pixel chain was proposed.A straight line was treated as an aggregation of several horizontal pixel chains or diagonal pixel chains.An algorithm of line drawing in a reverse direction,which was similar to Bresenham algorithm,was introduced,by which the slope between 0.5 and 1 was converted to that between 0 and 0.5 while generating line.One pixel chain was generated by one judgment.The simulation results show the straight line generated by new algorithm is as same as that generated by Bresenham algorithm,but the calculation is greatly reduced.The new algorithm has generated two integer arithmetic: addition and multiplication,and it is suitable for hardware implementation.The generation speed of the new algorithm is 4 times of Bresenham algorithm with the same complexity of design.

미술가들의 음영 표현 특성과 CG 쉐이딩 알고리즘 간의 상관관계 분석

최근 컴퓨터 그래픽스와 사용자의 인지를 결합한 다양한 연구들이 진행되고 있다. Cole 등은 미술가들의 라인 드로잉 데이터를 수집하여 기존의 CG(Computer-Generated) 라인 드로잉 알고리즘들이 미술가들의 드로잉 특성을 반영하고 있는지 비교하고, 사용자들이 어떤 라인 드로잉 알고리즘의 결과에서 형태를 효과적으로 인지하는지 평가하는 실험을 수행하였다. 그러나 라인 드로잉 알고리즘의 결과보다 BRDF 쉐이딩 모델이 적용된 결과에서 형태를 더욱 효과적으로 인지한다는 결과를 보였는데, 이는 음영이 형태 정보를 전단하기에 더욱 효과적인 요소임을 반증한다. 따라서 본 논문에서는 물체에서 인지한 음영과 미술가들의 음영 표현, 그리고 CG 쉐이딩 알고리즘 간의 상관관계에 대해서 연구한다. 특히, 미술가들의 음영 표현 특성과 CG 쉐이딩 알고리즘에서 나타나는 특성에 초점을 맞추고 이를 정량적으로 분석한다. 본 논문에서 수집한 실험 데이터 및 분석 결과는 효과적인 형태 전달을 목적으로 하는 새로운 CG 쉐이딩 알고리즘을 설계하는데 활용한 것으로 기대된다. Recently, several researchers have attempted to combine human visual perception and computer graphics. Cole et. al. suggest the study results in which line drawing algorithm in computer graphics characterize the properties of line drawing made by artists. The paper also evaluates CG line drawing algorithms depending on whether people recognize effectively specific 3D shape from the image made by those CG line drawing algorithms. However, human recognizes the shape of objects more effectively in image made by BRDF shading model than line drawing algorithm. It means that the shading factor is important to recognize shape with human perception. In this paper, we analyze the correlation between shading made by human artists and that made by CG shading algorithms. The study is to characterize the mathematical properties of artists' shading and CG shading. This type of analysis can guide the future development of new CG shading algorithm in computer graphics for the purpose of shape perception.

Line Drawing Algorithm on an Interleaved Grid

paper Bresenham's line drawing algorithm on interleaved grid is proposed. It uses the advantages of interleaved sampling to scan-convert the pixel on the raster with less representation error. The performance of the proposed algorithm is compared with the conventional Bresenham's algorithm on square grid. The qualitative and quantitative analyses show that the proposed algorithm outperforms the Bresenham's line drawing algorithm on square grid.