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Full-Text Articles in Computer Engineering
Ballot Mark Detection, Elisa H. Barney Smith, Daniel Lopresti, George Nagy
Ballot Mark Detection, Elisa H. Barney Smith, Daniel Lopresti, George Nagy
Electrical and Computer Engineering Faculty Publications and Presentations
Optical mark sensing, i.e., detecting whether a "bubble" has been filled in, may seem straightforward. However, on US election ballots the shape, intensity, size and position of the marks, while specified, are highly variable due to a diverse electorate. The ballots may be produced and scanned by poorly maintained equipment. Yet near-perfect results are required. To improve the current technology, which has been subject to criticism, components of a process for identifying marks on an optical sense ballot are evaluated. When marked synthetic ballots are compared to an unmarked ballot, the absolute difference of adaptive thresholded images gives best detection …
Text Degradations And Ocr Training, Elisa H. Barney Smith, Tim Andersen
Text Degradations And Ocr Training, Elisa H. Barney Smith, Tim Andersen
Electrical and Computer Engineering Faculty Publications and Presentations
Printing and scanning of text documents introduces degradations to the characters which can be modeled. Interestingly, certain combinations of the parameters that govern the degradations introduced by the printing and scanning process affect characters in such a way that the degraded characters have a similar appearance, while other degradations leave the characters with an appearance that is very different. It is well known that (generally speaking) a test set that more closely matches a training set will be recognized with higher accuracy than one that matches the training set less well. Likewise, classifiers tend to perform better on data sets …
Estimating Degradation Model Parameters From Character Images, Hok S. Yam, Elisa H. Barney Smith
Estimating Degradation Model Parameters From Character Images, Hok S. Yam, Elisa H. Barney Smith
Electrical and Computer Engineering Faculty Publications and Presentations
This paper discusses the use of character images to determine the parameters of an image degradation model. The acute angles in character images provide information used to find the model parameters. Three experiments are conducted to evaluate the use of characters. In the first experiment, large quantities of corners from character images are used to investigate how their contribution affects the mean and the standard deviation of the parameter estimators. In the second experiment, we focus on the relationship between the angles of the corners used in estimation and the estimation results. In the last experiment, we examine how likely …
Scanner Parameter Estimation Using Bilevel Scans Of Star Charts, Elisa H. Barney Smith
Scanner Parameter Estimation Using Bilevel Scans Of Star Charts, Elisa H. Barney Smith
Electrical and Computer Engineering Faculty Publications and Presentations
Scanning a high contrast image in bilevel mode results in image degradation. This is caused by two primary effects: blurring and thresholding. This paper expands on a method of estimating a joint distortion parameter, called the edge spread, from a star sector test chart in order to calculate the values of the point spread function width and binarization threshold. This theory is also described for variations in the source pattern which can represent degradations caused by repetition of the bilevel process as would be seen in printing then scanning, or in repeated photocopying. Estimation results are shown for the basic …