共查询到19条相似文献,搜索用时 15 毫秒
1.
Marcel Worring Arnold W.M. Smeulders 《International Journal on Document Analysis and Recognition》1999,1(4):209-220
When archives of paper documents are to be accessed via the Internet, the implicit hypertext structure of the original documents
should be employed. In this paper we study the different hypertext structures one encounters in a document. Methods for analyzing
paper documents to find these structures are presented. The structures also form the basis for the presentation of the content
of the document to the user. Results are presented.
Received October 13, 1998 / Revised February 15, 1999 相似文献
2.
Jayavel Shanmugasundaram Eugene Shekita Rimon Barr Michael Carey Bruce Lindsay Hamid Pirahesh Berthold Reinwald 《The VLDB Journal The International Journal on Very Large Data Bases》2001,10(2-3):133-154
XML is rapidly emerging as a standard for exchanging business data on the World Wide Web. For the foreseeable future, however,
most business data will continue to be stored in relational database systems. Consequently, if XML is to fulfill its potential,
some mechanism is needed to publish relational data as XML documents. Towards that goal, one of the major challenges is finding
a way to efficiently structure and tag data from one or more tables as a hierarchical XML document. Different alternatives
are possible depending on when this processing takes place and how much of it is done inside the relational engine. In this
paper, we characterize and study the performance of these alternatives. Among other things, we explore the use of new scalar
and aggregate functions in SQL for constructing complex XML documents directly in the relational engine. We also explore different
execution plans for generating the content of an XML document. The results of an experimental study show that constructing
XML documents inside the relational engine can have a significant performance benefit. Our results also show the superiority
of having the relational engine use what we call an “outer union plan” to generate the content of an XML document.
Received: 15 October 2000 / Accepted: 15 April 2001 Published online: 28 June 2001 相似文献
3.
Hideaki Goto Hirotomo Aso 《International Journal on Document Analysis and Recognition》2002,4(4):258-268
Recent remarkable progress in computer systems and printing devices has made it easier to produce printed documents with
various designs. Text characters are often printed on colored backgrounds, and sometimes on complex backgrounds such as photographs,
computer graphics, etc. Some methods have been developed for character pattern extraction from document images and scene images
with complex backgrounds. However, the previous methods are suitable only for extracting rather large characters, and the
processes often fail to extract small characters with thin strokes. This paper proposes a new method by which character patterns
can be extracted from document images with complex backgrounds. The method is based on local multilevel thresholding and pixel
labeling, and region growing. This framework is very useful for extracting character patterns from badly illuminated document
images. The performance of extracting small character patterns has been improved by suppressing the influence of mixed-color
pixels around character edges. Experimental results show that the method is capable of extracting very small character patterns
from main text blocks in various documents, separating characters and complex backgrounds, as long as the thickness of the
character strokes is more than about 1.5 pixels.
Received July 23, 2001 / Accepted November 5, 2001 相似文献
4.
Active rules for XML: A new paradigm for E-services 总被引:1,自引:0,他引:1
Angela Bonifati Stefano Ceri Stefano Paraboschi 《The VLDB Journal The International Journal on Very Large Data Bases》2001,10(1):39-47
XML is rapidly becoming one of the most widely adopted technologies for information exchange and representation. As the use
of XML becomes more widespread, we foresee the development of active XML rules, i.e., rules explicitly designed for the management
of XML information. In particular, we argue that active rules for XML offer a natural paradigm for the rapid development of
innovative e-services. In the paper, we show how active rules can be specified in the context of XSLT, a pattern-based language
for publishing XML documents (promoted by the W3C) which is receiving strong commercial support, and Lorel, a query language
for XML documents that is quite popular in the research world. We demonstrate, through simple examples of active rules for
XSLT and Lorel, that active rules can be effective for the implementation of e-commerce services. We also discuss the various
issues that need to be considered in adapting the notion of relational triggers to the XML context.
Received: 30 October 2000 / Accepted: 19 December 2000 Published online: 27 April 2001 相似文献
5.
Shuhua Wang Yang Cao Shijie Cai 《International Journal on Document Analysis and Recognition》2001,4(1):27-34
The most noticeable characteristic of a construction tender document is that its hierarchical architecture is not obviously
expressed but is implied in the citing information. Currently available methods cannot deal with such documents. In this paper,
the intra-page and inter-page relationships are analyzed in detail. The creation of citing relationships is essential to extracting
the logical structure of tender documents. The hierarchy of tender documents naturally leads to extracting and displaying
the logical structure as tree structure. This method is successfully implemented in VHTender, and is the key to the efficiency
and flexibility of the whole system.
Received February 28, 2000 / Revised October 20, 2000 相似文献
6.
Stefan Klink Thomas Kieninger 《International Journal on Document Analysis and Recognition》2001,4(1):18-26
Document image processing is a crucial process in office automation and begins at the ‘OCR’ phase with difficulties in document
‘analysis’ and ‘understanding’. This paper presents a hybrid and comprehensive approach to document structure analysis. Hybrid
in the sense that it makes use of layout (geometrical) as well as textual features of a given document. These features are
the base for potential conditions which in turn are used to express fuzzy matched rules of an underlying rule base. Rules
can be formulated based on features which might be observed within one specific layout object. However, rules can also express
dependencies between different layout objects. In addition to its rule driven analysis, which allows an easy adaptation to
specific domains with their specific logical objects, the system contains domain-independent markup algorithms for common
objects (e.g., lists).
Received June 19, 2000 / Revised November 8, 2000 相似文献
7.
8.
Amit Kumar Das Sanjoy Kumar Saha Bhabatosh Chanda 《International Journal on Document Analysis and Recognition》2002,4(3):183-190
Document image segmentation is the first step in document image analysis and understanding. One major problem centres on
the performance analysis of the evolving segmentation algorithms. The use of a standard document database maintained at the
Universities/Research Laboratories helps to solve the problem of getting authentic data sources and other information, but
some methodologies have to be used for performance analysis of the segmentation. We describe a new document model in terms
of a bounding box representation of its constituent parts and suggest an empirical measure of performance of a segmentation
algorithm based on this new graph-like model of the document. Besides the global error measures, the proposed method also
produces segment-wise details of common segmentation problems such as horizontal and vertical split and merge as well as invalid
and mismatched regions.
Received July 14, 2000 / Revised June 12, 2001[-1mm] 相似文献
9.
Katrin Franke Mario Köppen 《International Journal on Document Analysis and Recognition》2001,3(4):218-231
Computer-based forensic handwriting analysis requires sophisticated methods for the pre-processing of digitized paper documents,
in order to provide high-quality digitized handwriting, which represents the original handwritten product as accurately as
possible. Due to the requirement of processing a huge amount of different document types, neither a standardized queue of
processing stages, fixed parameter sets nor fixed image operations are qualified for such pre-processing methods. Thus, we
present an open layered framework that covers adaptation abilities at the parameter, operator, and algorithm levels. Moreover,
an embedded module, which uses genetic programming, might generate specific filters for background removal on-the-fly. The
framework is understood as an assistance system for forensic handwriting experts and has been in use by the Bundeskriminalamt,
the federal police bureau in Germany, for two years. In the following, the layered framework will be presented, fundamental
document-independent filters for textured, homogeneous background removal and for foreground removal will be described, as
well as aspects of the implementation. Results of the framework-application will also be given.
Received July 12, 2000 / Revised October 13, 2000 相似文献
10.
Hwan-Chul Park Se-Young Ok Young-Jung Yu Hwan-Gue Cho 《International Journal on Document Analysis and Recognition》2001,4(2):115-130
Automatic character recognition and image understanding of a given paper document are the main objectives of the computer
vision field. For these problems, a basic step is to isolate characters and group words from these isolated characters. In
this paper, we propose a new method for extracting characters from a mixed text/graphic machine-printed document and an algorithm
for distinguishing words from the isolated characters. For extracting characters, we exploit several features (size, elongation,
and density) of characters and propose a characteristic value for classification using the run-length frequency of the image
component. In the context of word grouping, previous works have largely been concerned with words which are placed on a horizontal
or vertical line. Our word grouping algorithm can group words which are on inclined lines, intersecting lines, and even curved
lines. To do this, we introduce the 3D neighborhood graph model which is very useful and efficient for character classification
and word grouping. In the 3D neighborhood graph model, each connected component of a text image segment is mapped onto 3D
space according to the area of the bounding box and positional information from the document. We conducted tests with more
than 20 English documents and more than ten oriental documents scanned from books, brochures, and magazines. Experimental
results show that more than 95% of words are successfully extracted from general documents, even in very complicated oriental
documents.
Received August 3, 2001 / Accepted August 8, 2001 相似文献
11.
Luiz Fernando G. Soares Rogério F. Rodrigues Débora C. Muchaluat Saade 《Multimedia Systems》2000,8(2):118-134
This paper discusses multimedia and hypermedia modeling, authoring and formatting tools, presenting the proposals of the
HyperProp system and comparing them to related work. It also highlights several research challenges that still need to be
addressed. Moreover, it stresses the importance of document logical structuring and considers the use of compositions in order
to represent context relations, synchronization relations, derivation relations and task relations in hypermedia systems.
It discusses temporal and spatial synchronization among multimedia objects and briefly presents the HyperProp graphical authoring
and formatting tools. Integration between the proposed system and the WWW is also addressed. 相似文献
12.
Henry S. Baird Allison L. Coates Richard J. Fateman 《International Journal on Document Analysis and Recognition》2003,5(2-3):158-163
Abstract. We exploit the gap in ability between human and machine vision systems to craft a family of automatic challenges that tell
human and machine users apart via graphical interfaces including Internet browsers. Turing proposed [Tur50] a method whereby
human judges might validate “artificial intelligence” by failing to distinguish between human and machine interlocutors. Stimulated
by the “chat room problem” posed by Udi Manber of Yahoo!, and influenced by the CAPTCHA project [BAL00] of Manuel Blum et
al. of Carnegie-Mellon Univ., we propose a variant of the Turing test using pessimal print: that is, low-quality images of machine-printed text synthesized pseudo-randomly over certain ranges of words, typefaces,
and image degradations. We show experimentally that judicious choice of these ranges can ensure that the images are legible
to human readers but illegible to several of the best present-day optical character recognition (OCR) machines. Our approach
is motivated by a decade of research on performance evaluation of OCR machines [RJN96,RNN99] and on quantitative stochastic
models of document image quality [Bai92,Kan96]. The slow pace of evolution of OCR and other species of machine vision over
many decades [NS96,Pav00] suggests that pessimal print will defy automated attack for many years. Applications include `bot'
barriers and database rationing.
Received: February 14, 2002 / Accepted: March 28, 2002
An expanded version of: A.L. Coates, H.S. Baird, R.J. Fateman (2001) Pessimal Print: a reverse Turing Test. In: {\it Proc.
6th Int. Conf. on Document Analysis and Recognition}, Seattle, Wash., USA, September 10–13, pp. 1154–1158
Correspondence to: H. S. Baird 相似文献
13.
Christian Shin David Doermann Azriel Rosenfeld 《International Journal on Document Analysis and Recognition》2001,3(4):232-247
Searching for documents by their type or genre is a natural way to enhance the effectiveness of document retrieval. The layout
of a document contains a significant amount of information that can be used to classify it by type in the absence of domain-specific
models. Our approach to classification is based on “visual similarity” of layout structure and is implemented by building
a supervised classifier, given examples of each class. We use image features such as percentages of text and non-text (graphics,
images, tables, and rulings) content regions, column structures, relative point sizes of fonts, density of content area, and
statistics of features of connected components which can be derived without class knowledge. In order to obtain class labels
for training samples, we conducted a study where subjects ranked document pages with respect to their resemblance to representative
page images. Class labels can also be assigned based on known document types, or can be defined by the user. We implemented
our classification scheme using decision tree classifiers and self-organizing maps.
Received June 15, 2000 / Revised November 15, 2000 相似文献
14.
Oleg Okun Matti Pietikäinen Jaakko Sauvola 《International Journal on Document Analysis and Recognition》1999,2(2-3):132-144
The existing skew estimation techniques usually assume that the input image is of high resolution and that the detectable
angle range is limited. We present a more generic solution for this task that overcomes these restrictions. Our method is
based on determination of the first eigenvector of the data covariance matrix. The solution comprises image resolution reduction,
connected component analysis, component classification using a fuzzy approach, and skew estimation. Experiments on a large
set of various document images and performance comparison with two Hough transform-based methods show a good accuracy and
robustness for our method.
Received October 10, 1998 / Revised version September 9, 1999 相似文献
15.
This paper presents a system for automatic generation of the adjacency matrix from the image of graphs. The graph, we assume,
is printed or hand printed and available as a part of a document either separately or along with text and picture. A morphology-based
approach is used here to separate components of the graphs: vertices, edges and labels. A novel technique is proposed to traverse
the nonplanar edges joining the vertices. The proposed method may be used for logical compression of the information contained
in the graph image in the form of an adjacency matrix. It may also be used to replace the cumbersome, error-prone and time-consuming
manual method of generation of the adjacency matrix for graphs with large number of vertices and complex interconnections. 相似文献
16.
Efficient extraction of primitives from line drawings composed of horizontal and vertical lines 总被引:6,自引:0,他引:6
The performance of the algorithms for the extraction of primitives for the interpretation of line drawings is usually affected
by the degradation of the information contained in the document due to factors such as low print contrast, defocusing, skew,
etc. In this paper, we are proposing two algorithms for the extraction of primitives with good performance under degradation.
The application of the algorithms is restricted to line drawings composed of horizontal and vertical lines. The performance
of the algorithms has been evaluated by using a protocol described in the literature.
Received: 6 August 1996 / Accepted: 16 July 1997 相似文献
17.
An information retrieval system that captures both visual and textual contents from paper documents can derive maximal benefits
from DAR techniques while demanding little human assistance to achieve its goals. This article discusses technical problems,
along with solution methods, and their integration into a well-performing system. The focus of the discussion is very difficult
applications, for example, Chinese and Japanese documents. Solution methods are also highlighted, with the emphasis placed
upon some new ideas, including window-based binarization using scale measures, document layout analysis for solving the multiple
constraint problem, and full-text searching techniques capable of evading machine recognition errors.
Received May 25, 2000 / Revised November 7, 2000 相似文献
18.
Pierre M. Devaux Daniel B. Lysak Rangachar Kasturi 《International Journal on Document Analysis and Recognition》1999,2(2-3):120-131
Converting paper-based engineering drawings into CAD model files is a tedious process. Therefore, automating the conversion
of such drawings represents tremendous time and labor savings. We present a complete system which interprets such 2D paper-based
engineering drawings, and outputs 3D models that can be displayed as wireframes. The system performs the detection of dimension
sets, the extraction of object lines, and the assembly of 3D objects from the extracted object lines. A knowledge-based method
is used to remove dimension sets and text from ANSI engineering drawings, a graphics recognition procedure is used to extract
complete object lines, and an evidential rule-based method is utilized to identify view relationships. While these methods
are the subject of several of our previous papers, this paper focuses on the 3D interpretation of the object. This is accomplished
using a technique based on evidential reasoning and a wide range of rules and heuristics. The system is limited to the interpretation
of objects composed of planar, spherical, and cylindrical surfaces. Experimental results are presented.
Received December 2, 1998 / Revised June 18, 1999 相似文献
19.
One key component in providing effective image data management support is an expressive query language/interface. In this
paper, we describe the EXQUISI system that we have developed. A main contribution of EXQUISI is its ability to allow a user
to express subtle differences that may exist between images to be retrieved and other images that are similar. In particular,
it allows the user to incorporate ambiguities and imprecisions in specifying his/her query. Another important aspect of EXQUISI
is the provision of a reformulation language by which the user can ask “like this in what” queries, by specifying which parts
of a returned image the user wants to include and exclude. 相似文献