The Experts below are selected from a list of 23820 Experts worldwide ranked by ideXlab platform
Habibollah Haron - One of the best experts on this subject based on the ideXlab platform.
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heuristic algorithm to generate modified freeman Chain Code from thinned binary image
Australian journal of basic and applied sciences, 2011Co-Authors: Haswadi Hasan, Habibollah Haron, Siti Zaiton Mohd HashimAbstract:Chain Code is an image representation which can be used to represent a shape of object or structure and also to represent connectivity between lines in the image boundary. It can be used in various applications because of its ability for information preservation and allows considerable storage space reduction for properties data image shape. This representation also can be applied in image processing field such as image compression, feature extraction and pattern recognition. Extracting Chain Code for boundary image or shape of object is simpler compared to extracting two-dimensional thinned binary image (TBI) that contain junctions. Thus, this paper presents a new Chain Code scheme and its algorithm to extract the Chain Code from TBI with multiple junctions. The importance of this Chain Code is mainly for feature extraction and recognition processes against such images. Before extracting the Chain Code, TBI with location-marked junctions is required as input data. This input data is a text file contains thinned binary image (0,1) plus junction marker, 'J' character to indicate a corner or junction at corresponding location. Junction positioning and labelling can be performed manually or by using corner/junction detection algorithm. Subsequently, the input file (0,1,J) will be traversed starting from image boundary and is followed by its inner line. In traversing process, all junction markers will be sequentially renamed to character A-Z to distinguish among existing junctions and, MFCC will be generated simultaneously. The peculiar way this MFCC is generated is due to feature extraction and recognition needs.
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improved vertex Chain Code based mapping algorithm for curve length estimation
Journal of Computer Science, 2011Co-Authors: Habibollah Haron, Lili Ayu Wulandhari, Amjad Rehman, Tanzila SabaAbstract:Problem statement: Image representation has always been an important and interesting topic in image processing and pattern recognition. However, curve tracing and its relative operations are the main bottleneck. Approach: This research presents the mapping algorithm that covers one of the vertex Chain Code cells, the rectangular-VCC cell. The mapping algorithm consists of a cell-representation algorithm that represents a thinned binary image in rectangular cells, a transcribing algorithm that transcribes the cells into vertex Chain Code and a validation algorithm that visualizes vertex Chain Code into rectangular cells. Results: The algorithms have been tested and validated by using three thinned binary images: L-block, hexagon and pentagon. Conclusion/Recommendations: The results show that this algorithm is capable of visualizing and transcribing them into vertex Chain Code.
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The framework of image recognition based on modified freeman Chain Code
2011Co-Authors: Haswadi Hasan, Habibollah Haron, Siti Zaiton Mohd HashimAbstract:Image recognition of line drawing involves feature extraction and feature comparison; works on the extraction required the representation of the image to be compared and analysed. Combining these two requirements, a framework that implements a new extraction algorithm of a Chain Code representation is presented. In addition, new corner detection is presented as pre-processing to the line drawing input in order to derive the Chain Code. This paper presents a new framework that consists of five steps namely pre-processing and image processing, new corner detection algorithm, Chain Code generator, feature extraction algorithm, and recognition process. Heuristic approach that is applied in the corner detection algorithm accepts thinned binary image as input and produces a modified thinned binary image containing J characters to represent corners in the image. Using the modified thinned binary image, a new Chain Code scheme that is based on Freeman Chain Code is proposed and an algorithm is developed to generate a single Chain Code series that is representing the line drawing input. The feature extraction algorithm is then extracts the three pre-defined features of the Chain Code for recognition purpose. The features are corner properties, distance between corners, and angle from a corner to the connected corner. The explanation of steps in the framework is supported with two line drawings. The results show that the framework successfully recognizes line drawing into five categories namely not similar line drawing, and four other categories that are similar but with attributes of rotation angle and scaling ratio.
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Characteristic of Rectangular Vertex Chain Code for Shapes with Hole
2009 International Conference on Information Management and Engineering, 2009Co-Authors: Lili Ayu Wulandhari, Habibollah HaronAbstract:Vertex Chain Code is one of image representation that was introduced by Bribiesca in 1999. Each Code in this Chain Code indicates the number of cell vertices, which are in touch with the bounding contour of the shape in that element position. It is possible to represent shape in triangular, rectangular and hexagonal cells in vertex Chain Code. A shape that is used in vertex Chain Code that is proposed by Bribiesca is a shape without hole. This paper will explained vertex Chain Code in rectangular cell for shape with hole. Some characteristic of rectangular vertex Chain Code for shape with hole is presented by using some example of shapes.
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Algorithm for Length Estimation Based on the Vertex Chain Code
2009 International Conference on Signal Processing Systems, 2009Co-Authors: Oldooz Dianat, Habibollah HaronAbstract:Image analysis deals with discrete picture, obtained by a process of digitization. Through this process, losing some information is inevitable. Length of a curve belongs to this category. Since the existence of digital image there are many algorithms proposed for estimating the length of the curve.Length estimation in digital image is tied to the method of digitization. We chose four-neighborhood digitization in two dimensions. This digitization makes it possible for length estimator to apply the Vertex Chain Code. A trace contour algorithm is applied to extract the Vertex Chain Code. The output is used for global length estimation, namely maximum length digital straight segments. In this paper we compare this global length estimator for both Freeman Chain Code and Vertex Chain Code.
Changwook Kim - One of the best experts on this subject based on the ideXlab platform.
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Unambiguous description of Chain Code picture languages
Information Processing Letters, 1996Co-Authors: Changwook KimAbstract:Abstract There exists a regular (context-free) Chain Code picture language which is not described by any picture-unambiguous regular (context-free) language. Every recursively enumerable Chain Code picture language is described by a picture-unambiguous context-sensitive language.
Borut Žalik - One of the best experts on this subject based on the ideXlab platform.
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Can burrows-Wheeler transform be replaced in Chain Code compression?
Information Sciences, 2020Co-Authors: Borut Žalik, Domen Mongus, Niko Lukač, Krista Rizman ŽalikAbstract:Abstract Burrows-Wheeler Transform, followed by Move-To-Front Transform, are often used transformation techniques in data compression. They may reduce the information entropy of the input sequence, which becomes more compressible in this way. This paper suggests an alternative, a Prediction-based Move-To-Front Transform, which may replace the aforementioned transformations. According to the context, consisting of a few already seen symbols, the Prediction-based Move-To-Front Transform selects an appropriate ordered domain of symbols to achieve a better match with the currently transforming symbol. Freeman Chain Code in four and eight directions, Three-Orthogonal Chain Code, and Vertex Chain Code were used for experiments. We confirmed that the proposed approach, when using an appropriate length of context, reduces the information entropy to a similar extent as the Burrows-Wheeler Transform followed by the Move-To-Front Transform on Chain Code data. Both approaches led to a very similar compression efficiency on 32 testing shapes when an arithmetic Coder was used in the final stage. The proposed approach turned out to be more efficient when longer Chain Code sequences were used, obtained by merging all the testing Chain Codes of the same type.
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efficient representation of geometric tree models with level of detail using compressed 3d Chain Code
IEEE Transactions on Visualization and Computer Graphics, 2019Co-Authors: Damjan Strnad, Stefan Kohek, Andrej Nerat, Borut ŽalikAbstract:: In the paper, we present a method for space-efficient representation of geometric tree models, which are provided as skeletons with radii attached to individual branch segments. The proposed approach uses a new differential 3D Chain Code to enCode orientation changes of consecutive branch segments, which allows optimizing Chain Code generation for increased compressibility while maintaining control over the model reconstruction error. The presented method is the first to enCode the complete branching geometry including the branch radii and provides level-of-detail construction directly from the Chain Code. It is demonstrated that by using interpolative encoding of the resulting tree descriptors and radii sequences, the storage requirements for geometric description of a mixed all-aged forest can be reduced to less than 15% of its raw size while preserving the structural fidelity of tree models.
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Chain Code compression with modified interpolative coding
Computers & Electrical Engineering, 2019Co-Authors: Borut Žalik, Niko Lukač, Krista Rizman Žalik, Eva Zupančič, Mitja Žalik, Domen MongusAbstract:Abstract A lossless Chain Code compression algorithm consisting of Burrows-Wheeler Transform, Move-To-Front Transform, and a modified interpolative coding is presented in this paper. The interpolative coding divides a strictly increasing array of integers and enCodes the middle element recursively, where the required number of bits is obtained from the difference of the array’s border values. In this paper, it is shown that, for some intervals, Golomb coding is more efficient than the interpolative coding. This fact was used to construct a hybrid approach that yields slightly better compression results than the state-of-the-art while compressing Three OrThogonal Chain Code, Freeman Chain Code in four and eight directions, and Vertex Chain Code.
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Efficient Chain Code compression with interpolative coding
Information Sciences, 2018Co-Authors: Borut Žalik, Domen Mongus, Niko Lukač, Krista Rizman ŽalikAbstract:Abstract This paper considers the use of interpolative coding for lossless Chain Code compression. The most popular Chain Codes are used, including Freeman Chain Code in eight (F8) and four directions (F4), Vertex Chain Code (VCC), and three-orthogonal Chain Code (3OT). The whole compression pipeline consists of the Burrows–Wheeler transform, Move-To-Front transform and the interpolative coding, which was improved by FELICS and new Ψ-coding. The approach was compared with the state-of-the-art Chain Code compression algorithms. For VCC, 3OT and F4, the obtained results are slightly better than the existing approaches. However, an important improvement was achieved with F8 Chain Code, where the presented approach is considerably better.
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Chain Code compression using string transformation techniques
Digital Signal Processing, 2016Co-Authors: Borut Žalik, Domen Mongus, Krista Rizman Žalik, Niko LukačAbstract:Abstract This paper considers the suitability of string transformation techniques for lossless Chain Codes' compression. The more popular Chain Codes are compressed including the Freeman Chain Code in four and eight directions, the vertex Chain Code, the three orthogonal Chain Code, and the normalised directional Chain Code. A testing environment consisting of the constant 0-symbol Run-Length Encoding ( RLE 0 L ), Move-To-Front Transformation (MTFT), and Burrows–Wheeler Transform (BWT) is proposed in order to develop a more suitable configuration of these techniques for each type of the considered Chain Code. Finally, a simple yet efficient entropy coding is proposed consisting of MTFT, followed by the Chain Code symbols' binarisation and the run-length encoding. PAQ8L compressor is also an option that can be considered in the final compression stage. Comparisons were done between the state-of-the-art including the Universal Chain Code Compression algorithm, Move-To-Front based algorithm, and an algorithm, based on the Markov model. Interesting conclusions were obtained from the experiments: the sequential uses of MTFT, RLE 0 L , and BWT are reasonable only in the cases of shorter Chain Codes' alphabets as with the vertex Chain Code and the three orthogonal Chain Code. For the remaining Chain Codes, BWT alone provided the best results. The experiments confirm that the proposed approach is comparable against other lossless Chain Code compression methods, while in total achieving higher compression rates.
Stefan Taubenberger - One of the best experts on this subject based on the ideXlab platform.
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TAGT - Chain-Code Pictures and Collages Generated by Hyperedge Replacement
Lecture Notes in Computer Science, 1996Co-Authors: Jürgen Dassow, Annegret Habel, Stefan TaubenbergerAbstract:Regular Chain-Code picture languages can be generated by collage grammars. As a consequence, all undecidability results known for regular Chain-Code languages can be adapted to picture languages generated by collage grammars.
Krista Rizman Žalik - One of the best experts on this subject based on the ideXlab platform.
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Can burrows-Wheeler transform be replaced in Chain Code compression?
Information Sciences, 2020Co-Authors: Borut Žalik, Domen Mongus, Niko Lukač, Krista Rizman ŽalikAbstract:Abstract Burrows-Wheeler Transform, followed by Move-To-Front Transform, are often used transformation techniques in data compression. They may reduce the information entropy of the input sequence, which becomes more compressible in this way. This paper suggests an alternative, a Prediction-based Move-To-Front Transform, which may replace the aforementioned transformations. According to the context, consisting of a few already seen symbols, the Prediction-based Move-To-Front Transform selects an appropriate ordered domain of symbols to achieve a better match with the currently transforming symbol. Freeman Chain Code in four and eight directions, Three-Orthogonal Chain Code, and Vertex Chain Code were used for experiments. We confirmed that the proposed approach, when using an appropriate length of context, reduces the information entropy to a similar extent as the Burrows-Wheeler Transform followed by the Move-To-Front Transform on Chain Code data. Both approaches led to a very similar compression efficiency on 32 testing shapes when an arithmetic Coder was used in the final stage. The proposed approach turned out to be more efficient when longer Chain Code sequences were used, obtained by merging all the testing Chain Codes of the same type.
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Chain Code compression with modified interpolative coding
Computers & Electrical Engineering, 2019Co-Authors: Borut Žalik, Niko Lukač, Krista Rizman Žalik, Eva Zupančič, Mitja Žalik, Domen MongusAbstract:Abstract A lossless Chain Code compression algorithm consisting of Burrows-Wheeler Transform, Move-To-Front Transform, and a modified interpolative coding is presented in this paper. The interpolative coding divides a strictly increasing array of integers and enCodes the middle element recursively, where the required number of bits is obtained from the difference of the array’s border values. In this paper, it is shown that, for some intervals, Golomb coding is more efficient than the interpolative coding. This fact was used to construct a hybrid approach that yields slightly better compression results than the state-of-the-art while compressing Three OrThogonal Chain Code, Freeman Chain Code in four and eight directions, and Vertex Chain Code.
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Efficient Chain Code compression with interpolative coding
Information Sciences, 2018Co-Authors: Borut Žalik, Domen Mongus, Niko Lukač, Krista Rizman ŽalikAbstract:Abstract This paper considers the use of interpolative coding for lossless Chain Code compression. The most popular Chain Codes are used, including Freeman Chain Code in eight (F8) and four directions (F4), Vertex Chain Code (VCC), and three-orthogonal Chain Code (3OT). The whole compression pipeline consists of the Burrows–Wheeler transform, Move-To-Front transform and the interpolative coding, which was improved by FELICS and new Ψ-coding. The approach was compared with the state-of-the-art Chain Code compression algorithms. For VCC, 3OT and F4, the obtained results are slightly better than the existing approaches. However, an important improvement was achieved with F8 Chain Code, where the presented approach is considerably better.
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Chain Code compression using string transformation techniques
Digital Signal Processing, 2016Co-Authors: Borut Žalik, Domen Mongus, Krista Rizman Žalik, Niko LukačAbstract:Abstract This paper considers the suitability of string transformation techniques for lossless Chain Codes' compression. The more popular Chain Codes are compressed including the Freeman Chain Code in four and eight directions, the vertex Chain Code, the three orthogonal Chain Code, and the normalised directional Chain Code. A testing environment consisting of the constant 0-symbol Run-Length Encoding ( RLE 0 L ), Move-To-Front Transformation (MTFT), and Burrows–Wheeler Transform (BWT) is proposed in order to develop a more suitable configuration of these techniques for each type of the considered Chain Code. Finally, a simple yet efficient entropy coding is proposed consisting of MTFT, followed by the Chain Code symbols' binarisation and the run-length encoding. PAQ8L compressor is also an option that can be considered in the final compression stage. Comparisons were done between the state-of-the-art including the Universal Chain Code Compression algorithm, Move-To-Front based algorithm, and an algorithm, based on the Markov model. Interesting conclusions were obtained from the experiments: the sequential uses of MTFT, RLE 0 L , and BWT are reasonable only in the cases of shorter Chain Codes' alphabets as with the vertex Chain Code and the three orthogonal Chain Code. For the remaining Chain Codes, BWT alone provided the best results. The experiments confirm that the proposed approach is comparable against other lossless Chain Code compression methods, while in total achieving higher compression rates.