Holistic word recognition in handwritten documents is an important research topic in the field of Document Image Analysis. For some applications, given strong language models, it can be more robust and computationally less expensive than character segmentation and recognition. This paper presents HH-CompWordNet, a novel approach to applying a Convolutional Neural Network (CNN) to directly to the DCT coefficients of the compressed domain word images. The efficacy of the HH-CompWordNet is demonstrated with the JPEG compressed version of the CMATERdb2.1.2.1 dataset - standard Handwritten Bangla word images. Experiments show the system obtains state-of-the-art accuracy of 86.80%.

Spatial verification is typically employed to check the spatial consistency among matched local features and to remove outliers. However, when looking for multiple instances of the query within a target image, RANSAC algorithms which are widely applied in many one-to-one matching applications might fail due to the large proportion of “outliers” - correct matches corresponding to other instances. On the other hand, geometrical verification methods are more robust to outliers but usually suffer from high computational costs. In this paper, we introduce a novel two-step line verification method which is more flexible than existing methods and leads to lower computational complexity especially when multiple instances of a query are sought. We study this approach within an information extraction scenario, where the objective is to locate document structures indicative of certain type of information (e.g. different records on invoices).

Given two versions of a document image, the goal of document image change detection is to automatically determine exactly what content was added, deleted or modified. Typically, one would accomplish this by first performing Optical Character Recognition (OCR) on the two documents and then performing a “diff” to identify the changes. However, this approach can fail due to OCR errors, poor segmentation, or the inability to handle graphical content. We compare the OCR baseline with two techniques based on SIFT features that detect changes in the image at the word level. The first approach performs the “diff” on SIFT features extracted from the center line of the text image. The second approach performs a segmentation free alignment of text blocks using dense SIFT to address the more general cases where segmentation fails or graphical objects are modified. Results on two experimental datasets show the improvement of the segmentation free approach over the baseline approach.

Automatic script identification from handwritten document images facilitates many important applications such as indexing, sorting and triage. A given Optical Character Recognition (OCR) system is typically trained on only a single script but for documents or collections containing different scripts, there must be some way to automatically identify the script prior to OCR. For Indic script research, some results have been reported in the literature but the task is far from solved. In this paper, we propose a word-level script identification technique for six handwritten Indic scripts- Bangla, Devanagari, Gurumukhi, Malayalam, Oriya Telugu and the Roman script. A set of 82 features has been designed using a combination of elliptical and polygonal approximation techniques. Our approach has been evaluated on a dataset of 7000 handwritten text words, using multiple classifiers. A Multi-Layer Perceptron (MLP) classifier was found to be the best classifier resulting in 95.35% accuracy. The result is progressive considering the complexities and shape variations of the Indic scripts.

In this paper, we propose a fast large-scale signature matching method based on locality sensitive hashing (LSH). Shape Context features are used to describe the structure of signatures. Two stages of hashing are performed to find the nearest neighbours for query signatures. In the first stage, we use M randomly generated hyper planes to separate shape context feature points into different bins, and compute a term-frequency histogram to represent the feature point distribution as a feature vector. In the second stage we again use LSH to categorize the high-level features into different classes. The experiments are carried out on two datasets - DS-I, a small dataset contains 189 signatures, and DS-II, a large dataset created by our group which contains 26,000 signatures. We show that our algorithm can achieve a high accuracy even when few signatures are collected from one same person and perform fast matching when dealing with a large dataset.

This paper explores the related problems of verification and change detection in document images. The goal is to determine if two document images differ, and if so, to determine precisely what content may have been added, deleted, or otherwise modified. This problem has many potential applications, especially for important legal documents such as contractual agreements. These agreements are often edited, shared and stored as scanned or hardcopy documents, where small, undetected changes between edits could create major differences in the contractual language and thus have severe repercussions. One can view the problem of change detection as tracing the revision history of a set of documents. Thus, in order to validate the performance of this approach, we created the "Enron Revisions" dataset. This dataset contains realistic revisions obtained from attachments in the Enron Corpus, and a series of before and after snapshots of the revisions in images with varying levels of noise from resolution, binarization, and blur. The approach taken in this paper utilizes the SIFT descriptor to align two document images without the benefit of OCR and once aligned, to compare dense descriptors to determine changes that have occurred within the image. As a baseline, this "VisualDiff" is compared to a UNIX diff-like approach on text extracted through OCR and results demonstrate the effectiveness of this approach.

This paper presents a new method for writer identification, which emulates the approach taken by forensic document examiners. It combines a novel feature, which uses contour gradients to capture local shape and curvature, with character segmentation to create a pseudo-alphabet for a given handwriting sample. A distance metric is then defined between elements of these alphabets that captures character similarity between two handwriting samples. This approach achieves a Top-1 identification rate of 96.5% on the benchmark IAM dataset, reducing the error rate of previous approaches by 50%.

In this paper, we present a learning based approach for computing structural similarities among document images for unsupervised exploration in large document collections. The approach is based on multiple levels of content and structure. At a local level, a bag-of-visual words based on SURF features provides an effective way of computing content similarity. The document is then recursively partitioned and a histogram of codewords is computed for each partition. Structural similarity is computed using a random forest classifier trained with these histogram features. We experiment with three diverse datasets of document images varying in size, degree of structural similarity, and types of document images. Our results demonstrate that the proposed approach provides an effective general framework for grouping structurally similar document images.

To maintain, control and enhance the quality of document images and minimize the negative impact of degradations on various analysis and processing systems, it is critical to understand the types and sources of degradations and develop reliable methods for estimating the levels of degradations. This paper provides a brief survey of research on the topic of document image quality assessment. We first present a detailed analysis of the types and sources of document degradations. We then review techniques for document image degradation modeling. Finally, we discuss objective measures and subjective experiments that are used to characterize document image quality.

This paper presents a scalable algorithm for segmentation free logo retrieval in document images. The contributions include the use of the SURF feature for logo retrieval, a novel indexing algorithm for efficient retrieval and a method to filter results using the orientation of local features and geometric constraints. Results demonstrate that logo retrieval can be performed with high accuracy and efficiently scaled to a large datasets.

We propose a contour based shape decomposition approach that provides local segmentation of touching characters. The shape contour is linearized into edge lets and edge lets are merged into boundary fragments. The connection cost between boundary fragments is obtained by considering local smoothness, connection length and a stroke-level property called the Same Stroke Rate. Samples of connections among boundary fragments are randomly generated and the one with the minimum global cost is selected to produce the final segmentation of the shape. To obtain a bipartite segmentation using this approach, we perform an iterative search for the parameters that finally yields two components on a shape. Experimental results on synthetic shape images and the LTP dataset show that this contour based shape decomposition technique is promising and it is effective for providing local segmentation of touching characters.

This paper presents a two-phased stroke-like pattern noise (SPN) removal algorithm for binary document images. The proposed approach aims at understanding script-independent prominent text component features using supervised classification as a first step. It then uses their cohesiveness and stroke-width properties to filter and associate smaller text components with them using an unsupervised classification technique. In order to perform text extraction, and hence noise removal, at diacritic-level, this divide-and-conquer technique does not assume the availability of accurate and large amounts of ground-truth data at component-level for training purposes. The method was tested on a collection of degraded and noisy, machine-printed and handwritten binary Arabic text documents. Results show pixel-level precision and recall of 86% and 90% respectively for noise-pixels.

This paper presents a method for performing offline writer identification by using K-adjacent segment (KAS) features in a bag-of-features framework to model a user's handwriting. This approach achieves a top 1 recognition rate of 93% on the benchmark IAM English handwriting dataset, which outperforms current state of the art features. Results further demonstrate that identification performance improves as the number of training samples increase, and additionally, that the performance of the KAS features extend to Arabic handwriting found in the MADCAT dataset.

In this paper, we present a template based approach to the segmentation of touching components in handwritten text lines. Local patches around touching components are identified and a dictionary is created consisting of template patches together with their correct segmentations. We use two shape context based methods to compute similarity between input patches and dictionary templates to find the best match. The template's known segmentation is then transformed to segment the input patch. Experiments are carried on a dataset of touching text lines.

In this paper, we present a fast and effective method for removing pre-printed rule-lines in handwritten document images. We use an integral-image representation which allows fast computation of features and apply techniques for large scale Support Vector learning using a data selection strategy to sample a small subset of training data. Results on both constructed and real-world data sets show that the method is effective for rule-line removal. We compare our method to a subspace-based method and show that better accuracy can be achieved in considerably less time. The integral-image based features proposed in the paper are generic and can be applied to other problems as well.

This paper presents an approach to text line extraction in handwritten document images which combines local and global techniques. We propose a graph-based technique to detect touching and proximity errors that are common with handwritten text lines. In a refinement step, we use Expectation-Maximization (EM) to iteratively split the error segments to obtain correct text-lines. We show improvement in accuracies using our correction method on datasets of Arabic document images. Results on a set of artificially generated proximity images show that the method is effective for handling touching errors in handwritten document images.

The labeling of large sets of images for training or testing analysis systems can be a very costly and time-consuming process. Multiple instance learning (MIL) is a generalization of traditional supervised learning which relaxes the need for exact labels on training instances. Instead, the labels are required only for a set of instances known as bags. In this paper, we apply MIL to the retrieval and localization of signatures and the retrieval of images containing machine-printed text, and show that a gain of 15-20% in performance can be achieved over the supervised learning with weak-labeling. We also compare our approach to supervised learning with fully annotated training data and report a competitive accuracy for MIL. Using our experiments on real-world datasets, we show that MIL is a good alternative when the training data has only document-level annotation.

This paper presents a dynamic approach to document page segmentation based on inter-component relationships, local patterns and context features. State-of-the art page segmentation algorithms segment zones based on local properties of neighboring connected components such as distance and orientation, and do not typically consider additional properties other than size. Our proposed approach uses a contextually aware and dynamically adaptive page segmentation scheme. The page is first over-segmented using a dynamically adaptive scheme of separation features based on [2] and adapted from [13]. A decision to form zones is then based on the context built from these local separation features and high-level content features. Zone-based evaluation was performed on sets of printed and handwritten documents in English and Arabic scripts with multiple font types, sizes and we achieved an increase of 15% over the accuracy reported in [2].

In this paper, we present a novel graph-based method for extracting handwritten text lines in monochromatic Arabic document images. Our approach consists of two steps - Coarse text line estimation using primary components which define the line and assignment of diacritic components which are more difficult to associate with a given line. We first estimate local orientation at each primary component to build a sparse similarity graph. We then, use a shortest path algorithm to compute similarities between non-neighboring components. From this graph, we obtain coarse text lines using two estimates obtained from Affinity propagation and Breadth-first search. In the second step, we assign secondary components to each text line. The proposed method is very fast and robust to non-uniform skew and character size variations, normally present in handwritten text lines. We evaluate our method using a pixel-matching criteria, and report 96% accuracy on a dataset of 125 Arabic document images. We also present a proximity analysis on datasets generated by artificially decreasing the spacings between text lines to demonstrate the robustness of our approach.

In this paper we present a novel method for removing page rule lines in monochromatic handwritten Arabic documents using subspace methods with minimal effect on the quality of the foreground text. We use moment and histogram properties to extract features that represent the characteristics of the underlying rule lines. A linear subspace is incrementally built to obtain a line model that can be used to identify rule line pixels. We also introduce a novel scheme for evaluating noise removal algorithms in general and we use it to assess the quality of our rule line removal algorithm. Experimental results presented on a data set of 50 Arabic documents, handwritten by different writers, demonstrate the effectiveness of the proposed method.

The paper presents a clutter detection and removal algorithm for complex document images. The distance transform based approach is independent of clutter's position, size, shape and connectivity with text. Features are based on a residual image obtained by analysis of the distance transform and clutter elements, if present, are identified with an SVM classifier. Removal is restrictive, so text attached to the clutter is not deleted in the process. The method was tested on a collection of degraded and noisy, machine-printed and handwritten Arabic and English text documents. Results show pixel-level accuracies of 97.5% and 95% for clutter detection and removal respectively. This approach was also extended with a noise detection and removal model for documents having a mix of clutter and salt-n-pepper noise.

This paper presents a dynamic approach to document page segmentation. Current page segmentation algorithms lack the ability to dynamically adapt local variations in the size, orientation and distance of components within a page. Our approach builds upon one of the best algorithms, Kise et. al. work based on Area Voronoi Diagrams, which adapts globally to page content to determine algorithm parameters. In our approach, local thresholds are determined dynamically based on parabolic relations between components, and Docstrum based angular and neighborhood features are integrated to improve accuracy. Zone-based evaluation was performed on four sets of printed and handwritten documents in English and Arabic scripts and an increase of 33% in accuracy is reported.

Graphics detection and recognition are fundamental research problems in document image analysis and retrieval. As one of the most pervasive graphical elements in business and government documents, logos may enable immediate identification of organizational entities and serve extensively as a declaration of a document's source and ownership. In this work, we developed an automatic logo-based document image retrieval system that handles: (1) Logo detection and segmentation by boosting a cascade of classifiers across multiple image scales; and (2) Logo matching using translation, scale, and rotation invariant shape descriptors and matching algorithms. Our approach is segmentation free and layout independent and we address logo retrieval in an unconstrained setting of 2D feature point matching. Finally, we quantitatively evaluate the effectiveness of our approach using large collections of real-world complex document images.

We have developed a font-model based intelligent character segmentation and recognition system. Using characteristics of structurally similar TrueType fonts, our system automatically builds a model to be used for the segmentation and recognition of the new script, independent of glyph composition. The key is a reliance on known font attributes. In our system three feature extraction methods are used to demonstrate the importance of appropriate features for classification. The methods are tested on both Latin (English) and non-Latin (Khmer) scripts. Results show that the character-level recognition accuracy exceeds 92\% for Khmer and 96\% for English on degraded documents. This work is a step toward the recognition of scripts of low-density languages which typically do not warrant the development of commercial OCR, yet often have complete TrueType font descriptions.

Automatic logo detection and recognition continues to be of great interest to the document retrieval community as it enables effective identification of the source of a document. In this paper, we propose a new approach to logo detection and extraction in document images that robustly classifies and precisely localizes logos using a boosting strategy across multiple image scales. At a coarse scale, a trained Fisher classifier performs initial classification using features from document context and connected components. Each logo candidate region is further classified at successively finer scales by a cascade of simple classifiers, which allows false alarms to be discarded and the detected region to be refined. Our approach is segmentation free and lay-out independent. We define a meaningful evaluation metric to measure the quality of logo detection using labeled groundtruth. We demonstrate the effectiveness of our approach using a large collection of real-world documents.

This paper describes the development of a new document ranking system based on layout similarity. The user has a need represented by a set of "wanted" documents, and the system ranks documents in the collection according to this need. Rather than performing complete document analysis, the system extracts text lines, and models layouts as relationships between pairs of these lines. This paper explores three novel feature sets to support scoring in large document collections. First, pairs of lines are used to form quadrilaterals, which are represented by their turning functions. A non-Euclidean distance is used to measure similarity. Second, the quadrilaterals are represented by 5D Euclidean vectors, and third, each line is represented by a 5D Euclidean vector. We compare the classification performance and computation speed of these three feature sets using a large database of diverse documents including forms, academic papers and handwritten pages in English and Arabic. The approach using quadrilaterals and turning functions produces slightly better results, but the approach using vectors to represent text lines is much faster for large document databases.

In this paper, we present a multiple classifier system for script identification. Applying a Gabor filter analysis of textures on word-level, our system identifies Latin and non-Latin words in bilingual printed documents. The classifier system comprises four different architectures based on nearest neighbors, weighted Euclidean distances, Gaussian mixture models, and support vector machines. We report results for Arabic, Chinese, Hindi, and Korean script. Moreover, we show that combining informational confidence values using sum-rule can consistently outperform the best single recognition rate.

Most studies on combining multiple classifiers have focused on combination methods, but a few studies have investigated on how to select component classifiers from a classifier pool. Multiple classifier systems performance varies with the component classifiers as well as the combination method. In this paper, methods based on information theory are proposed for selecting component classifiers, provided that the number of component classifiers is fixed in advance. These methods are applied to the classifier pool and examine the possible classifier sets. The system is compared to other multiple classifier systems on the recognition of unconstrained handwritten numerals.

A methodology is proposed for processing noisy printed documents with limited user feedback. Without the support of ground truth, a specific collection of scanned documents can be processed to extract character templates. The adaptiveness of this approach lies in that the extracted templates are used to train an OCR classifier quickly and with limited user feedback. Experimental results show that this approach is extremely useful for the processing of noisy documents with many touching characters.

Since it is extremely expensive to collect a large volume of handwriting samples, synthesized data are often used to enlarge the training set. We argue that, in order to generate good handwriting samples, a synthesis algorithm should learn the shape deformation characteristics of handwriting from real samples. In this paper, we present a point matching algorithm to learn the deformation, and apply it to handwriting synthesis. Preliminary experiments show the advantages of our approach.

Test collections model use cases in ways that facilitate evaluation of information retrieval systems. This paper describes the use of search-guided relevance assessment to create a test collection for retrieval of spontaneous conversational speech. Approximately 10,000 thematically coherent segments were manually identified in 625 hours of oral history interviews with 246 individuals. Automatic speech recognition results, manually prepared summaries, controlled vocabulary indexing, and name authority control are available for every segment. Those features were leveraged by a team of four relevance assessors to identify topically relevant segments for 28 topics developed from actual user requests. Search-guided assessment yielded sufficient inter-annotator agreement to support formative evaluation during system development. Baseline results for ranked retrieval are presented to illustrate use of the collection.

The increasing availability of high performance, low priced, portable digital imaging devices has created a tremendous opportunity for supplementing traditional scanning for document image acquisition. Digital cameras attached to cellular phones, PDAs, or as standalone still or video devices are highly mobile and easy to use; they can capture images of any kind of document including very thick books, historical pages too fragile to touch, and text in scenes; and they are much more versatile than desktop scanners. Should robust solutions to the analysis of documents captured with such devices become available, there is clearly a demand from many domains. Traditional scanner-based document analysis techniques provide us with a good reference and starting point, but they cannot be used directly on camera-captured images. Camera captured images can suffer from low resolution, blur, and perspective distortion, as well as complex layout and interaction of the content and background. In this paper we present a survey of application domains, technical challenges and solutions for recognizing documents captured by digital cameras. We begin by describing typical imaging devices and the imaging process. We discuss document analysis from a single camera-captured image as well as multiple frames and highlight some sample applications under development and feasible ideas for future development.

Without an independence assumption, combining multiple classifiers deals with a high order probability distribution composed of classifiers and a class label. Storing and estimating the high order probability distribution is exponentially complex and unmanageable in theoretical analysis, so we rely on an approximation scheme using the dependency. In this paper, as an extension of the second-order dependency approach, the probability distribution is optimally approximated by the third-order dependency and multiple classifiers are combined. The proposed method is evaluated on the recognition of unconstrained handwritten numerals from Concordia University and the University of California, Irvine. Experimental results support the proposed method as a promising approach.

The performance of multiple classifier systems varieswith the performance of component classifiers as well asthe method of combination. In this paper, information-theoreticmethods are proposed for constructing multipleclassifier systems, provided that the number of componentclassifiers is constrained in advance. These proposed methodsare applied to a classifier pool and examine the possibleclassifier sets by the selected information-theoretic criteria.One of them is then selected as the candidate and isevaluated together with the other multiple classifier systemson the recognition of unconstrained handwritten numeralsfrom Concordia University and the University of California,Irvine. Experimental results support the approach.

When scanning documents with a large number of pagessuch as books, it is often feasible to provide a minimalnumber of training samples to personalize the system tocompensate for global shifts in how the document wascreated or in scanning parameters. In this paper, wepresent a supervised multi-class classifier based onGabor filters that is used to classify the scripts, font-faces,and font-styles (bold, italic, normal etc.) in anapplication where the classes are known. Classificationis performed at the word level (glyphs separated by whitespace) given training samples of each class. This methodwas applied to a variety of bilingual dictionaries toidentify different scripts, and simultaneously, to classifyRoman scripts into bold, italic and normal font-styles.Experimental results show the effectiveness of thisapproach in increasing performance over classifierstrained for general documents.

In this paper we present a novel model based approach to detect severely broken parallel lines in noisy textual documents. It is important to detect and remove these lines so the text can be segmented and recognized. We use directional single-connected chain, a vectorization based algorithm, to extract the line segments. We then instantiate a parallel line model with three parameters: the skew angle, the vertical line gap, and the vertical translation. A coarse-to-fine approach is used to improve the estimation accuracy. From the model we can incorporate the high level contextual information to enhance detection results even when lines are severely broken. Our experimental results show our method can detect 94% of the lines in our database with 168 noisy Arabic document images.

In this paper we address the problem of the identification of text from noisy documents. We segment and identify handwriting from machine printed text because 1) handwriting in a document often indicates corrections, additions or other supplemental information that should be treated differently from the main body or body content, and 2) the segmentation and recognition techniques for machine printed text and handwriting are significantly different. Our novelty is that we treat noise as a separate class and model noise based on selected features. Trained Fisher classifiers are used to identify machine printed text and handwriting from noise. We further exploit context to refine the classification. A Markov random field (MRF) based approach is used to model the geometrical structure of the printed text, handwriting and noise to rectify the mis-classification. Experimental results show our approach is promising and robust, and can significantly improve the page segmentation results in noise documents.

We present a probabilistic framework for document analysis and recognition and illustrate it on the problem of musical score recognition. Our system uses an explicit descriptive model of the document class to find the most likely interpretation of a scanned document image. In contrast to the traditional pipeline architecture, we carry out all stages of the analysis with a single inference engine, allowing for an end-to-end propagation of the uncertainty. The global modeling structure is similar to a stochastic attribute grammar, and local parameters are estimated using hidden Markov models.

This paper proposes a strategy for analyzing unknown, filled forms. First, horizontal and vertical line segments are detected, extracted and filtered. A recursive splitting and merging algorithm eliminates overlapping segments, filters false segments, and groups the segments into lines. Based on the extracted lines, an algorithm for rectangle extraction is proposed. We define the constraints between rectangles and edges. In a process of scanning the horizontal and vertical lines, candidate edges are validated and rectangles are generated if its surrounding edges and their combination are all valid. The process is recursively applied. It can tolerate large breaks in form lines, ignore irrelevant segments and deal with embedded rectangles. Experiments on a collection of forms show that our approach works well on poor quality images.

The economic feasibility of creating large databases of document images has left a tremendous need for robust ways to access the information these images contain. Printed documents are often scanned for archiving or an an attempt to move toward a paper-less office and stored as images, but without adequate index information. In order to make full use of the capabilities of traditional database indexing and retrieval techniques, a full conversion of the document may be required. There are many factors, however, which may prohibit complete conversion including its high cost, insufficient document quality, or the fact that parts of the document can simply not be adequately represented in a converted form. In this paper, we provide a survey of methods developed by researchers to access document images without relying on complete and accurate conversion. We briefly discuss traditional text indexing techniques on imperfect data and the retrieval of partially converted documents, followed by a more complete review of techniques for the direct retrieval and characterization of document images including text, drawings and graphics.

We propose and implement a method for detecting duplicate documents in very large image databases. The method is based on a robust "signature" extracted from each document image which is used to index into a table of previously processed documents. The approach has a number of advantages over OCR or other recognition based methods, including speed and robustness to imaging distortions. To justify the approach and test the scalability, we have developed a simulator which allows us to change parameters of the system and examine performance for millions of document signatures. A complete system is implemented and tested on a test collection of technical articles and memos.

The purpose of a document is to facilitate the transfer of information from its author to its readers. It is the author's job to design the document so that the information it contains can be interpreted accurately and efficiently. To do this, the author can make use of a set of stylistic tools. In this paper, we introduce the concept of document functionality, which attempts to describe the roles of documents and their components in the process of transferring information. A functional description of a document provides insight into the type of the document, into its intended uses, and into strategies for automatic document interpretation and retrieval. To demonstrate these ideas, we define a taxonomy of functional document components and show how functional descriptions can be used to reverse-engineer the intentions of the author, to navigate in document space, and to provide important contextual information to aid in interpretation.

Progress on the problem of signature verification has advanced more rapidly in online applications than offline applications, in part because information which can easily be recorded in online environments, such as pen position and velocity, is lost in static offline data. In offline applications, valuable information which can be used to discriminate between genuine and forged signatures is embedded at the stroke level. We present an approach to segmenting strokes into stylistically meaningful segments and establish a local correspondence between a questioned signature and a reference signature to enable the analysis and comparison of stroke features. Questioned signatures which do not conform to the reference signature are identified as random forgeries. Most simple forgeries can also be identified, as they do not conform to the reference signature's invariant properties such as connections between letters. Since we have access to both local and global information, our approach also shows promise for extension to the identification of skilled forgeries.

We describe a new approach to manage the testing of document analysis and understanding applications. We propose and present a collection of document images, a set of techniques to prepare the test cases interactively and means to control the testing process. The systems architecture is designed to be distributed, scalable and platform independent utilizing Java, C++ and object-oriented databases. The main features of this system are a basic document categorization and ground truth, degradation models, custom test case creation facilities, a test management module (pipelining, test history), the ability to embed document analysis algorithms into the system, remote usage facilities and robust graphical user interfaces.

Work has recently begun on a joint project between the Universities of Maryland and Oulu on the development of a system for Intelligent Document Image Retrieval (IDIR). The IDIR system will provide close connections with and utilization of document analysis and image processing techniques, advanced computing and networking, and modern approaches to database management. The system design consists of aggressively modularized components to enhance the development of individual parts which are used in the complete solution, including: Interface specifications, multipurpose feature extraction, an integrated efficient query language, physical retrieval from an object-oriented database, and delivery of retrieved objects. In this paper, we introduce the general framework, feature extraction modules, query capabilities, a graphical query interface, and the application interface. We demonstrate each component of the system and how the query mechanisms can be used to handle both content and struc...

Table form document structure analysis is an important problem in the document processing domain. The paper presents a method called Box Driven Reasoning (BDR) to robustly analyze the structure of table form documents which include touching characters and broken lines. Most previous methods employ a line oriented approach. Real documents are copied repeatedly and overlaid with printed data, resulting in characters which touch cells and lines which are broken. BDR deals with regions directly, in contrast with other previous methods. Experimental tests show that BDR reliably recognizes cells and strings in document images with touching characters and broken lines.

An approach to image based typographic analysis of documents is provided. The problem requires a spatial understanding of the document layout as well as knowledge of the proper syntax. The system performs a page synthesis from the stream of formatting commands defined in a DVI file. Since the two-dimensional relationships between document components are not explicit in the page language, the authors develop a representation which preserves the two-dimensional layout, the read-order and the attributes of document components. From this hierarchical representation of the page layout we extract and analyze relevant typographic features such as margins, line and character spacing, and figure placement.>

An overview of an approach to the generic modeling and processing of known forms is presented. The system provides a methodology by which models are generated from regions in the document based on their usage. Automatic extraction of an optimal set of features to be used for registration is proposed, and it is shown how specialized detectors can be designed for each feature based on their position, orientation and width properties. Registration of the form with the model is accomplished using probing to establish correspondence. Form components which are corrupted by markings are detected and isolated, the intersections are interpreted and the properties of the non-form markings are used to reconstruct the strokes through the intersections. The feasibility of these ideas is demonstrated through an implementation of key components of the system.>

The problem of logo recognition is of great interest in the document domain, especially for databases, because of its potential for identifying the source of the document and its generality as a recognition problem. By recognizing the logo, one obtains semantic information about the document, which may be useful in deciding whether or not to analyze the textual components. A multi-level stages approach to logo recognition which uses global invariants to prune the database and local affine invariants to obtain a more refined match is presented. An invariant signature which can be used for matching under a variety of transformations is obtained. The authors provide a method of computing Euclidean invariants and show how to extend them to capture similarity, affine, and projective invariants when necessary. They implement feature detection, feature extraction, and local invariant algorithms and successfully demonstrate the approach on a small database.>