7 research outputs found
A hybrid approach for line segmentation in handwritten documents
This paper presents an approach for text line segmentation which combines connected component based and projection based information to take advantage of aspects of both methods. The proposed system finds baselines of each connected component. Lines are detected by grouping baselines of connected components belonging to each line by projection information. Components are assigned to lines according to different distance metrics with respect to their size. This study is one of the rare studies that apply line segmentation to Ottoman documents. Further, it proposes a new method, Fourier curve fitting, to detect the peaks in a projection profile. The algorithm is demonstrated on different printed and handwritten Ottoman datasets. Results show that the method manages to segment lines both from printed and handwritten documents under different writing conditions at least with 92% accuracy. © 2012 IEEE
A parallel windowing approach to the Hough transform for line segment detection
In the wide range of image processing and computer vision problems, line segment detection has always been among the most critical headlines. Detection of primitives such as linear features and straight edges has diverse applications in many image understanding and perception tasks. The research presented in this dissertation is a contribution to the detection of straight-line segments by identifying the location of their endpoints within a two-dimensional digital image. The proposed method is based on a unique domain-crossing approach that takes both image and parameter domain information into consideration. First, the straight-line parameters, i.e. location and orientation, have been identified using an advanced Fourier-based Hough transform. As well as producing more accurate and robust detection of straight-lines, this method has been proven to have better efficiency in terms of computational time in comparison with the standard Hough transform. Second, for each straight-line a window-of-interest is designed in the image domain and the disturbance caused by the other neighbouring segments is removed to capture the Hough transform buttery of the target segment. In this way, for each straight-line a separate buttery is constructed. The boundary of the buttery wings are further smoothed and approximated by a curve fitting approach. Finally, segments endpoints were identified using buttery boundary points and the Hough transform peak. Experimental results on synthetic and real images have shown that the proposed method enjoys a superior performance compared with the existing similar representative works
Recognition of off-line handwritten cursive text
The author presents novel algorithms to design unconstrained handwriting
recognition systems organized in three parts:
In Part One, novel algorithms are presented for processing of Arabic text prior to
recognition. Algorithms are described to convert a thinned image of a stroke to a straight
line approximation. Novel heuristic algorithms and novel theorems are presented to
determine start and end vertices of an off-line image of a stroke. A straight line
approximation of an off-line stroke is converted to a one-dimensional representation by
a novel algorithm which aims to recover the original sequence of writing. The resulting
ordering of the stroke segments is a suitable preprocessed representation for subsequent
handwriting recognition algorithms as it helps to segment the stroke. The algorithm was
tested against one data set of isolated handwritten characters and another data set of
cursive handwriting, each provided by 20 subjects, and has been 91.9% and 91.8%
successful for these two data sets, respectively.
In Part Two, an entirely novel fuzzy set-sequential machine character recognition
system is presented. Fuzzy sequential machines are defined to work as recognizers of
handwritten strokes. An algorithm to obtain a deterministic fuzzy sequential machine from
a stroke representation, that is capable of recognizing that stroke and its variants, is
presented. An algorithm is developed to merge two fuzzy machines into one machine. The
learning algorithm is a combination of many described algorithms. The system was tested
against isolated handwritten characters provided by 20 subjects resulting in 95.8%
recognition rate which is encouraging and shows that the system is highly flexible in
dealing with shape and size variations.
In Part Three, also an entirely novel text recognition system, capable of recognizing
off-line handwritten Arabic cursive text having a high variability is presented. This system
is an extension of the above recognition system. Tokens are extracted from a onedimensional
representation of a stroke. Fuzzy sequential machines are defined to work as
recognizers of tokens. It is shown how to obtain a deterministic fuzzy sequential machine
from a token representation that is capable'of recognizing that token and its variants. An
algorithm for token learning is presented. The tokens of a stroke are re-combined to
meaningful strings of tokens. Algorithms to recognize and learn token strings are
described. The. recognition stage uses algorithms of the learning stage. The process of
extracting the best set of basic shapes which represent the best set of token strings that
constitute an unknown stroke is described. A method is developed to extract lines from
pages of handwritten text, arrange main strokes of extracted lines in the same order as
they were written, and present secondary strokes to main strokes. Presented secondary
strokes are combined with basic shapes to obtain the final characters by formulating and
solving assignment problems for this purpose. Some secondary strokes which remain
unassigned are individually manipulated. The system was tested against the handwritings
of 20 subjects yielding overall subword and character recognition rates of 55.4% and
51.1%, respectively
A review of the open queueing network models of manufacturing systems
"December 1990."Includes bibliographical references (p. 52-58).Research partially supported by the "Leaders for Manufacturing Program". Research partially supported by the UCLA Senate Committee on Grants. 99by Gabriel R. Bitran, Sriram Dasu
Towards Efficient Ice Surface Localization From Hockey Broadcast Video
Using computer vision-based technology in ice hockey has recently been embraced as it allows for the automatic collection of analytics. This data would be too expensive and time-consuming to otherwise collect manually. The insights gained from these analytics allow for a more in-depth understanding of the game, which can influence coaching and management decisions. A fundamental component of automatically deriving analytics from hockey broadcast video is ice rink localization. In broadcast video of hockey games, the camera pans, tilts, and zooms to follow the play. To compensate for this motion and get the absolute locations of the players and puck on the ice, an ice rink localization pipeline must find the perspective transform that maps each frame to an overhead view of the rink.
The lack of publicly available datasets makes it difficult to perform research into ice rink localization. A novel annotation tool and dataset are presented, which includes 7,721 frames from National Hockey League game broadcasts.
Since ice rink localization is a component of a full hockey analytics pipeline, it is important that these methods be as efficient as possible to reduce the run time. Small neural networks that reduce inference time while maintaining high accuracy can be used as an intermediate step to perform ice rink localization by segmenting the lines from the playing surface.
Ice rink localization methods tend to infer the camera calibration of each frame in a broadcast sequence individually. This results in perturbations in the output of the pipeline, as there is no consideration of the camera calibrations of the frames before and after in the sequence. One way to reduce the noise in the output is to add a post-processing step after the ice has been localized to smooth the camera parameters and closely simulate the camera’s motion. Several methods for extracting the pan, tilt, and zoom from the perspective transform matrix are explored. The camera parameters obtained from the inferred perspective transform can be smoothed to give a visually coherent video output. Deep neural networks have allowed for the development of architectures that can perform several tasks at once. A basis for networks that can regress the ice rink localization parameters and simultaneously smooth them is presented.
This research provides several approaches for improving ice rink localization methods. Specifically, the analytics pipelines can become faster and provide better results visually. This can allow for improved insight into hockey games, which can increase the performance of the hockey team with reduced cost
Extending the p16-Leiden tumour spectrum by respiratory tract tumours
Text line extraction is one of the critical steps in document analysis and optical character recognition (OCR) systems. The purpose of this study is to address the problem of text line extraction of ancient Thai manuscripts written on palm leaves, using an Adaptive Partial Projection (APP) technique by integrating a modified partial projection and smooth histogram with recursion. The proposed approach was compared with a Modified Partial Projection (MPP) looking at vowel analysis and touching components of two consecutive lines. The results from this research suggested that the proposed approach for practical data on palm leaf manuscripts has better performance in solving the line segmentation problem