Character Alignment Research Articles

Noise-aware Character Alignment for Extracting Transliteration Fragments

Noise-aware Character Alignment for Extracting Transliteration Fragments

레벤스타인 거리 기반의 위치 정확도를 이용하여 다중 음성 인식 결과에서 관련성이 적은 후보 제거

Many isolated word recognition systems may generate irrelevant words for recognition results because they use only acoustic information or small amount of language information. In this paper, I propose word similarity that is used for selecting (or removing) less common words from candidates by applying Levenshtein distance. Word similarity is obtained by using positional accuracy that reflects the frequency information along to character's alignment information. This paper also discusses various improving techniques of selection of disparate words. The methods include different loss values, phone accuracy based on confusion information, weights of candidates by ranking order and partial comparisons. Through experiments, I found that the proposed methods are effective for removing heterogeneous words without loss of performance.

Text String Detection From Natural Scenes by Structure-Based Partition and Grouping

Text information in natural scene images serves as important clues for many image-based applications such as scene understanding, content-based image retrieval, assistive navigation, and automatic geocoding. However, locating text from a complex background with multiple colors is a challenging task. In this paper, we explore a new framework to detect text strings with arbitrary orientations in complex natural scene images. Our proposed framework of text string detection consists of two steps: 1) image partition to find text character candidates based on local gradient features and color uniformity of character components and 2) character candidate grouping to detect text strings based on joint structural features of text characters in each text string such as character size differences, distances between neighboring characters, and character alignment. By assuming that a text string has at least three characters, we propose two algorithms of text string detection: 1) adjacent character grouping method and 2) text line grouping method. The adjacent character grouping method calculates the sibling groups of each character candidate as string segments and then merges the intersecting sibling groups into text string. The text line grouping method performs Hough transform to fit text line among the centroids of text candidates. Each fitted text line describes the orientation of a potential text string. The detected text string is presented by a rectangle region covering all characters whose centroids are cascaded in its text line. To improve efficiency and accuracy, our algorithms are carried out in multi-scales. The proposed methods outperform the state-of-the-art results on the public Robust Reading Dataset, which contains text only in horizontal orientation. Furthermore, the effectiveness of our methods to detect text strings with arbitrary orientations is evaluated on the Oriented Scene Text Dataset collected by ourselves containing text strings in nonhorizontal orientations.

Phylogenetic utility of ycf1 in orchids: a plastid gene more variable than matK

Plastid DNA sequences have been widely used by systematists for reconstructing plant phylogenies. The utility of any DNA region for phylogenetic analysis is determined by ease of amplification and sequencing, confidence of assessment in phylogenetic character alignment, and by variability across broad taxon sampling. Often, a compromise must be made between using relatively highly conserved coding regions or highly variable introns and intergenic spacers. Analyses of a combination of these types of DNA regions yield phylogenetic structure at various levels of a tree (i.e., along the spine and at the tips of the branches). Here, we demonstrate the phylogenetic utility of a heretofore unused portion of a plastid protein-coding gene, hypothetical chloroplast open reading frame 1 (ycf1), in orchids. All portions of ycf1 examined are highly variable, yet alignable across Orchidaceae, and are phylogenetically informative at the level of species. In Orchidaceae, ycf1 is more variable than matK both in total number of parsimony informative characters and in percent variability. The nrITS region is more variable than ycf1, but is more difficult to align. Although we only demonstrate the phylogenetic utility of ycf1 in orchids, it is likely to be similarly useful among other plant taxa.

Dot Matrix Pairwise Sequence Comparison

INTRODUCTIONA dot matrix analysis is primarily a method for comparing two sequences to look for possible alignment of characters between the sequences. The method is also used for finding direct or inverted repeats in protein and DNA sequences, and for predicting regions in RNA that are self-complementary and that, therefore, have the potential of forming secondary structure through base-pairing.

License plate recognition using gray image template matching with noise reduction filters and character alignment

AbstractThis paper proposes a license plate recognition method using multivalued (gray image) template matching, which operates stably even under adverse illumination conditions in which the image contrast is easily degraded. The conventional method has been based on image binarization and the character extraction, which involves the problem that recognition accuracy is greatly lowered when the quality of the input image is degraded. To overcome this problem, the whole configuration of the recognition system is reviewed, and the following two‐stage method is considered. First, the individual characters are recognized. Multivalued template matching [log‐derivative‐matching (LDM) method], including a noise suppression filter based on nonlinear transformation of the gray levels and spatial frequency filtering, is used to scan the whole image. The character candidates and their locations are identified with high accuracy. Second, the license plate is recognized as follows. The likelihood of character existence for each coordinate obtained by image scanning and the character alignment rules in the license plate are compared, and the location with the highest likelihood of being the whole character string is selected. A comparison experiment was performed with more than 10,000 images taken in various outdoor illumination conditions, and it was shown that the recognition rate of the proposed method was much higher than that of the conventional method. The recognition rate for the four main digits was higher than 99% when minimum additional lighting was used, and nearly 95% under very severe illumination conditions. © 2007 Wiley Periodicals, Inc. Syst Comp Jpn, 38(3): 49– 61, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20342

Detection of courtesy amount block on bank checks

A multi-staged technique for locating the courtesy amount block on bank checks is presented. In the case of a check processing system, many of the proposed methods are not acceptable, due to the the presence of many fonts and text sizes, as well as the short length of many text strings. Particular methods chosen to implement a courtesy amount block locator (CABL) are described. First, the connected components in the image are identified. Next, strings are constructed on the basis of proximity and horizontal alignment of characters. Finally, a set of rules and heuristics are applied to these strings to choose the correct one. The chosen string is only reported if it passes a verification test, which includes an attempt to recognize the currency sign.

Character Alignment for High-Capacity PCM Systems Using MS43 Line Code

Alphabetic pseudoternary codes, which are being used largely for high-capacity pulse-code modulation (PCM) transmission, require character alignment of the received ternary sequence for correct conversion from pseudoternary to straight binary. In this paper a method and a strategy of character alignment for MS43 line code are proposed. The method is based on the recognition of the constraints and correlations involved by the conversion rules of MS43; the strategy, which is similar to that already used for frame alignment in PCM time-division-multiplex (PCM-TDM) systems, allows limiting of the effects of simulations and line errors on the processes of loss and recovery of character alignment. Statistical properties of these processes are analyzed both theoretically and by computer simulation. The results are used to design the character alignment strategy for a 34.368 Mbit/s PCM system using MS43 as line code.