复杂背景图像的文本信息提取研究
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摘要
图像中的文本包含大量有价值的信息,是智能控制系统和信息检测与检索系统的重要处理对象。手机及各种便捷式图像获取设备的普及使得越来越多的信息载体以图像或视频的形式存在,让计算机代替人来处理、识别和理解图像中所包含的文字信息有强烈的应用需求,然而计算机对图像文本信息的识别和理解能力与实际应用要求尚有不小的距离。图像中文本信息的有效提取一直受到研究者的关注,尤其是复杂背景中的文本信息提取技术依然是急需解决的技术难题。
     本文研究工作着眼于对手机和相机等便携设备拍摄的具有复杂背景的图像中检测和定位文本信息,通过分析复杂背景图像中文本的固有特性,研究了三种文本检测和定位算法,实现了一个文本信息提取与识别系统。本文的主要研究成果和贡献包括:
     (1)提出了一种基于纹理和统计特征的文本检测和定位方法。采用简化的均值偏移方法对图像进行平滑滤波,对图像进行去噪的同时能保留变化相对较强的细节信息:在边缘图像中根据文本的纹理特性构建像素的笔划特征,去除非文本像素;利用文本的统计特征,去除非文本区域块。实验表明,该算法具有较快的速度和较高的召回率,尤其对处于复杂背景或与背景粘连的文本比较有效。
     (2)提出了一种基于改进的视觉关注模型的文本检测和定位方法。对Itti视觉关注模型进行了改进,一是高斯金字塔的层数可以根据图像的大小自动调整;二是根据字符的特性选择强度特征图作为显著图,去掉可能弱化文本区域的归一化过程;三是为了突出显著图中的细节信息,获取显著图的时候对特征图进行上采样,得到与源图像尺寸相同的显著图。利用字符边缘点的方向分布呈对称性的特点对连通元做初步过滤后,采用显著图作为掩膜来验证候选文本区域的真伪。实验表明,该算法具有较好的检测性能,能够有效地检测出对比度较弱的文本区域。
     (3)提出了一种基于尺度空间的文本检测和定位的方法。改进了边缘检测的模板,将4个方向的Sobel算子模板中两个对角线方向的模板替换为对应方向的脊线算子模板,以改善文本和背景粘连的处理效果。利用尺度空间中拉普拉斯-高斯算子最大响应值的特性来滤除非文本块,该响应值在尺度上往往和字符的笔划宽度对应,并且分布在笔划的交界和末端,利用候选文本区域的笔划宽度作为启发条件,寻找尺度空间中是否有对应的较强响应点存在,结合这些点的分布情况滤除非文本区域。实验结果表明该算法具有较高的精确度。
     (4)实现了一个自然场景图像中的文本自动检测与识别系统。对于输入的自然场景图像首先利用文本检测和定位方法给出图像中的文本区域,然后对检测出的文本区域在二值化后进行尺度归一化处理,最后利用一个字符识别软件提取出文本区域中的文字信息。
     (5)对三种文本检测和定位方法的性能做了比较和分析,并实验表明每种方法各有优缺点,基于纹理和统计特征的文本检测和定位方法的整体性能指标虽然低于其余两种方法,但该方法对于复杂文本背景的图像比较有效;基于视觉关注模型的文本检测和定位方法的性能稍逊于基于尺度空间的文本检测和定位的方法,但该方法能够成功检测出对比度较弱的文本区域;基于尺度空间的文本检测和定位方法的整体性能指标最高,尤其是在精确度上具有优势,能够有效去除和文本类似的背景区域。
Text data in image play a significant role in the intelligent control system and information detection and retrieval system because they contain plenty of valuable information. More and more information appear as image or video with the increasing application of mobile and portable image capturing devices. It is urgent to endow computer with the abilities of processing, identifying and understanding text information in images. However, computer's capability of recognizing and understanding the text information cannot meet the requirements of the practical application. Researchers have paid their attentions on efficiently extracting the text information for long time. Especially, the extraction of the text information from the complicated background is still an open issue.
     This paper focuses on extracting and locating the text information contained in the images with complicated backgrounds. The images are captured by portable devices. Analyzing the intrinsic property of the text-in the scene images, we propose three methods for extracting and locating text in scene images, and implement a text extraction and recognition system. The contributions of this paper are as follows:
     (1) A text locating method based on texture and statistic features is proposed. The simplified mean shift algorithm is used to smooth the input image, which can remove the noise and reserve the strong detail information of the image. The edge map of the image is obtained to extract the stroke feature to filter non text pixels, while the statistic features of the blocks are employed to filter non text blocks. Experiments show that this method is fast with high recall. It is efficient for detecting the characters which adhere to the complicated background.
     (2) A text locating method based a modified visual attention model is presented. Itti's visual attention model is modified:First, the Gaussian pyramid can adjust its number of the layer according to the size of the input image; Second, the intense conspicuity is applied to be the saliency map, and its normalization is left out in case of weak text regions; Third, the saliency map, with the same size as the input image, is yielded by up-sampling the feature maps to stand out the detail information. The connected components are filtered by the Histogram of Oriented Gradient feature. The saliency map is then employed to filer the non-text regions. Experiments demonstrate that the method is capable of detecting the text regions with low contrast and achieving good performance.
     (3) A text locating method based on the sale space is proposed. The four templates of Sobel edge detector are modified by replacing the two diagonal Sobel templates with Ridge templates to avoid the adhesion of the text with the background. The property of the strongest responses is used to filter the non text regions. The responses, locating on the crosses or the endpoints of the strokes, always correspond to the stroke width of the character. Therefore, the stroke width of the candidate regions is applied to be the heuristic condition to search the related stronger responses in the scale space. The non text regions can be filtered by the distribution of the response. Experimental results prove that this method has high precision.
     (4) An automatic text detection and recognition system of the natural scene images is implemented. The text locating method is used to obtain the text regions of the input natural scene image. Then, the scale normalization is applied on the detected text region after being binarized. Finally, an OCR package is employed to extract the text information of the detected text regions.
     (5)The performances of the above three methods are compared and discussed. Experiments indicate that each method has advantages and disadvantages. The method based on the texture and statistic features is efficient for the images with complicated background although its performance is worse than the other two; The method based on modified visual attention model can successfully detect the low contrast text regions in spite of the fact that it is a little worse performance compared with the method based on the scale space. The method based on the scale space is capable of removing the text like background, with the highest whole performance, especially the precision.
引文
[1]H.K. Kim. Efficient automatic text location method and content-based indexing and structuring of video database[J]. Journal of Visual Communication Image Representation,1996,7(4):336-344.
    [2]P. Shivakumara, T.Q. Phan, C.L. Tan. A laplacian approach to multi-oriented text detection in video[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence, 2011,33(2):412-419.
    [3]A. K. Jain, B. Yu. Automatic text location in images and video frames[J]. Pattern Recognition,1998,31(12):2055-2076.
    [4]R. Lienhart. Video OCR: a survey and practitioner's guide. Kluwer Academic Publisher,2003.
    [5]K. Jung, K. I. Kim, A. K. Jain. Text information extraction in images and video:a survey[J]. Pattern Recognition,2004,37(5):977-997.
    [6]J. Liang, D. Doermann, H. Li. Camera-based analysis of text and documents:a survey[J]. International Journal on Document Analysis and Recognition,2005,7(2): 84-104.
    [7]J. Zhang, R. Kasturi. Text detection using edge gradient and graph spectrum[C]. In Proceedings of International Conference on Pattern Recognition,2010:3979-3982.
    [8]李闯.复杂背景图像中文字检测普适算法的研究[D].北京清华大学,2006.
    [9]Chunmei Liu, Chunheng Wang, Ruwei Dai. Text detection in images based on unsupervised classification of edge-based features[C]. In Proceedings of International Conference on Document Analysis and Recognition,2005:610-614.
    [10]C. Yi, Y. Tian. Text string detection from natural scenes by structure-based partition and grouping[J]. IEEE Transactions on Image Processing,2011,20(9):2594-2605.
    [11]L. Zini, A. Destrero, F. Odone. A classification architecture based on connected components for text detection in unconstrained environments[C]. In Proceedings of International Conference on Advanced Video and Signal Based Surveillance,2009: 176-181.
    [12]S.H. Lee, M.S. Cho, K. Jung, J.H. Kim. Scene text extraction with edge constraint and text collinearity[C]. In Proceedings of International Conference on Pattern Recognition,2010:3983-3986.
    [13]Y.F. Pan, X. Hou, C.L. Liu. Text localization in natural scene images based on conditional random field[C]. In Proceedings of International Conference on Document Analysis and Recognition,2009:6-10.
    [14]X. Gao, X. Tang. Automatic news video caption extraction and recognition[C]. In Proceedings of International Conference on Intelligent Data Engineering and Automated Learning — Data Mining, Financial Engineering, and Intelligent Agents 2000:425-430.
    [15]R. J. Jiang, F. H. Qi, L. Xu, G. R. Wu, K. H. Zhu. A learning-based method to detect and segment text from scene images[J]. Journal of Zhejiang University-Science A, 2007,8(4):568-574.
    [16]Y. Zhao, T. Lu, W. Liao. A robust color-independent text detection method from complex videos[C]. In Proceedings of International Conference on Document Analysis and Recognition,2011:374-378.
    [17]G. Zhou, Y. Liu, Z. Tian, Y. Su. A new hybrid method to detect text in natural scene[C]. In Proceedings of International Conference on Image Processing,2012: 2605-2608.
    [18]H. Dujmic, M. Saric, J. Radic. Scene text extraction using modified cylindrical distance[J]. Recent Researches in Neural Networks, Fuzzy Systems, Evolutionary Computing and Automation,2011,12:213-218.
    [19]Yu Zhong, Kalle Karu, Anil K. Jain. Locating text in complex color images[J]. Pattern Recognition,1995,28(10):1523-1535.
    [20]K. Sobottka, H. Bunke, H. Kronenberg. Identification of text on colored book and journal covers[C]. In Proceedings of International Conference on Document Analysis and Recognition,1999:57-62.
    [21]V. Y. Mariano, R. Kasturi. Locating uniform-colored text in video frames[C]. In Proceedings of International Conference on Pattern Recognition,2000:539-542.
    [22]U. Bhattacharya, S. K. Parui, S. Mondal. Devanagari and bangla text extraction from natural scene images[C]. In Proceedings of International Conference on Document Analysis and Recognition,2009:171-175.
    [23]D. Karatzas, A. Antonacopoulos. Colour text segmentation in web images based on human perception[J]. Image and Vision Computing,2007,25(5):564-577.
    [24]S.M. Lucas, A. Panaretos, L. Sosa, A. Tang, S. Wong, R. Young. ICDAR 2003 robust reading competitions[C]. In Proceedings of International Conference on Document Analysis and Recognition,2003:682-687.
    [25]Yunxue Shao, Chunheng Wang, Baihua Xiao, Yang Zhang, Linbo Zhang, Long Ma. Text detection in natural images based on character classification, in Advances in Multimedia Information Processing - PCM 2010[M], G. Qiu, et al., Editors. Springer Berlin/Heidelberg 2011:736-746.
    [26]J. Zhang, R. Kasturi. Character energy and link energy-based text extraction in scene images[C]. In Proceedings of Asian Conference on Computer Vision,2010:308-320.
    [27]X. Zhang, F. Sun. Pulse Coupled Neural Network Edge-Based Algorithm for Image Text Locating*[J]. Tsinghua Science & Technology,2011,16(1):22-30.
    [28]S.P. Chowdhury, S. Dhar, A.K. Das, B. Chanda, K. McMenemy. Robust extraction of text from camera images[C]. In Proceedings of International Conference on Document Analysis and Recognition,2009:1280-1284.
    [29]Cai Min, Song Jiqiang, M. R. Lyu. A new approach for video text detection[C]. In Proceedings of International Conference on Image Processing 2002:117-120
    [30]Palaiahnakote Shivakumara, Weihua Huang, Chew Lim Tan. Efficient video text detection using edge features[C]. In Proceedings of International Conference on Pattern Recognition,2008:1-4.
    [31]B. Epshtein, E. Ofek, Y. Wexler. Detecting text in natural scenes with stroke width transform[C]. In Proceedings of IEEE Conference on Computer Vision and Pattern Recognition 2010:2963-2970.
    [32]A. Ikica, P. Peer. An improved edge profile based method for text detection in images of natural scenes[C]. In Proceedings of International Conference on Computer as a Tool,2011:1-4.
    [33]E. K. Wong, M. Chen. A new robust algorithm for video text extraction[J]. Pattern Recognition,2003,36(6):1397-1406.
    [34]Anubhav Kumar, Awanish Kr Kaushik, R. L. Yadav, Anuradha. A robust and fast text extraction in images and video frames, in Advances in Computing, Communication and Control[M], S. Unnikrishnan, S. Surve, and D. Bhoir, Editors. Springer Berlin Heidelberg 2011:342-348.
    [35]M. Anthimopoulos, B. Gatos, I. Pratikakis. A two-stage scheme for text detection in video images[J]. Image and Vision Computing,2010,28(9):1413-1426.
    [36]B.T. Chun, Y. Bae, T.Y. Kim. Automatic text extraction in digital videos using FFT and neural network[C]. In Proceedings of IEEE International Conference on Fuzzy Systems 1999:1112-1115
    [37]Y. Zhong, H. Zhang, A.K. Jain. Automatic caption localization in compressed video[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence,2000,22(4): 385-392.
    [38]D. Crandall, S. Antani, R. Kasturi. Extraction of special effects caption text events from digital video[J]. International Journal on Document Analysis and Recognition, 2003,5(2):138-157.
    [39]Qixiang Ye, Qingming Huang, Wen Gao, Debin Zhao. Fast and robust text detection in images and video frames[J]. Image and Vision Computing,2005,23(6):565-76.
    [40]P. Shivakumara, T.Q. Phan, C.L. Tan. New Wavelet and Color Features for Text Detection in Video[C]. In Proceedings of International Conference on Pattern Recognition,2010:3996-3999.
    [41]Y. Fang, C. Deyun, W. Rui. Text feature extraction of natural scenes using Gabor wavelet transformation based on scale overlapping[C]. In Proceedings of International Forum on Strategic Technology 2011:1062-1064.
    [42]A.K. Jain, S. Bhattacharjee. Text segmentation using Gabor filters for automatic document processing[J]. Machine Vision and Applications,1992,5(3):169-184.
    [43]C. Mancas-Thillou, B. Gosselin. Color text extraction with selective metric-based clustering[J]. Computer Vision and Image Understanding,2007,107(1-2):97-107.
    [44]P. Clark, M. Mirmehdi. Finding text regions using localised measures[C]. In Proceedings of British Machine Vision Conference,2000:675-684.
    [45]V. Wu, R. Manmatha, E. M. Riseman. TextFinder: an automatic system to detect and recognize text in images[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence,1999,21(11):1224-1229.
    [46]K.I. Kim, K. Jung, J.H. Kim. Texture-based approach for text detection in images using support vector machines and continuously adaptive mean shift algorithm[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence 2003:1631-1639.
    [47]C. Jung, Q. Liu, J. Kim. A stroke filter and its application to text localization[J]. Pattern Recognition Letters,2009,30(2):114-122.
    [48]J. M. Zhang, J. Wang, J. Zhang, D. Du, F. Fang. Video text location method based on conditional stroke density extraction[J]. Computer Engineering and Design,2011, 32(10):3446-3449.
    [49]L. Xiaopei, L. Zhaoyang, L. Jing. Scene text location using gradient difference and character stroke width[J]. American Journal of Engineering and Technology Research, 2011,11(12).
    [50]L. Neumann, J. Matas. A method for text localization and recognition in real-world images[C]. In Proceedings of Asian Conference on Computer Vision,2010:770-783.
    [51]H. Bai, J. Sun, S. Naoi, Y. Katsuyama, Y. Hotta, K. Fujimoto. Video caption duration extraction[C]. In Proceedings of International Conference on Pattern Recognition, 2008:1-4.
    [52]C. Jung, Q. Liu, J. Kim. A new approach for text segmentation using a stroke filter[J]. Signal Processing,2008,88(7):1907-1916.
    [53]C. Zhu, W. Wang, Q. Ning. Text detection in images using texture feature from strokes[J]. Advances in Multimedia Information Processing-PCM 2006,2006: 295-301.
    [54]S.M. Hanif, L. Prevost. Text detection and localization in complex scene images using constrained adaboost algorithm[C]. In Proceedings of International Conference on Document Analysis and Recognition,2009:1-5.
    [55]Z. Tu, X. Chen, A.L. Yuille, S.C. Zhu. Image parsing: unifying segmentation, detection, and recognition[J]. International Journal of Computer Vision,2005,63(2): 113-140.
    [56]C.W. Lee, K. Jung, H.J. Kim. Automatic text detection and removal in video sequences[J]. Pattern Recognition Letters,2003,24(15):2607-2623.
    [57]D. Chen, J. M. Odobez, J. P. Thiran. A localization/verification scheme for finding text in images and video frames based on contrast independent features and machine learning methods[J]. Signal Processing:Image Communication,2004,19(3):205-217.
    [58]D. Chen, H. Bourlard, J. P. Thiran. Text identification in complex background using SVM[C]. In Proceedings of IEEE Conference on Computer Vision and Pattern Recognition,2001:621-626.
    [59]X. Chen, A.L. Yuille. Detecting and reading text in natural scenes[C]. In Proceedings of IEEE Computer Society Conference on Computer Vision and Pattern Recognition 2004:366-373.
    [60]K. Jung. Neural network-based text location in color images[J]. Pattern Recognition Letters,2001,22(14):1503-1515.
    [61]X. Tang, X. Gao, J. Liu, H. Zhang. A spatial-temporal approach for video caption detection and recognition[J]. IEEE Transactions on Neural Networks,2002,13(4): 961-971.
    [62]H. Li, D. Doermann, O. Kia. Automatic text detection and tracking in digital video[J]. IEEE Transactions on Image Processing,2000,9(1):147-156.
    [63]P. Shivakumara, W. Huang, T. Quy Phan, C. Lim Tan. Accurate video text detection through classification of low and high contrast images[J]. Pattern Recognition,2010, 43(6):2165-2185.
    [64]X. Wang, L. Huang, C. Liu. A new block partitioned text feature for text verification[C]. In Proceedings of International Conference on Document Analysis and Recognition,2009:366-370.
    [65]X. Wang, L. Huang, C. Liu. A video text location method based on background classification[J]. International Journal on Document Analysis and Recognition,2010, 13(3):1-14.
    [66]A. Mishra, K. Alahari, C. V. Jawahar. Top-down and bottom-up cues for scene text recognition[C]. In Proceedings of IEEE Conference on Computer Vision and Pattern Recognition,2012:2687-2694.
    [67]J. J. Weinman. Typographical features for scene text recognition[C]. In Proceedings of International Conference on Pattern Recognition,2010:3987-3990.
    [68]J. J. Weinman, E. Learned-Miller, A. R. Hanson. Scene text recognition using similarity and a lexicon with sparse belief propagation[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence,2009,31(10):1733-1746.
    [69]L. Neumann, J. Matas. Real-time scene text localization and recognition[C]. In Proceedings of IEEE Conference on Computer Vision and Pattern Recognition,2012: 3538-3545.
    [70]R. Lienhart, W. Effelsberg. Automatic text segmentation and text recognition for video indexing[J]. Multimedia Systems,2000,8(1):69-81.
    [71]C. Wolf, J. M. Jolion. Extraction and recognition of artificial text in multimedia documents[J]. Pattern Analysis & Applications,2004,6(4):309-326.
    [72]C. Wolf, J. M. Jolion, F. Chassaing. Text location, enhancement and binarization in multimedia documents[C]. In Proceedings of International Conference on Pattern Recognition,2002:1037-1040.
    [73]B. Amarapur, N. Patil. Video text extraction from images for character recognition[C]. In Proceedings of Canadian Conference on Electrical and Computer Engineering, 2006:198-201.
    [74]D. Chen, J. M. Olobez, H. Bourlard. Text segmentation and recognition in complex background based on markov random field[C]. In Proceedings of International Conference on Pattern Recognition,2002:227-230.
    [75]A. Coates, B. Carpenter, C. Case, S. Satheesh, B. Suresh, T. Wang, D. J. Wu, A. Y. Ng. Text detection and character recognition in scene images with unsupervised feature learning[C]. In Proceedings of International Conference on Document Analysis and Recognition,2011:440-445.
    [76]A. Antonacopoulos, B. Gatos, D. Karatzas, Society Ieee Computer. ICDAR 2003 page segmentation competition[C]. In Proceedings of International Conference on Document Analysis and Recognition,2003:688-692.
    [77]L. Wenyin, D. Dori. A protocol for performance evaluation of line detection algorithms [J]. Machine Vision and Applications,1997,9(5-6):240-250.
    [78]C. Wolf, J.M. Jolion. Object count/area graphs for the evaluation of object detection and segmentation algorithms[J]. International Journal on Document Analysis and Recognition,2006,8(4):280-296.
    [79]H. El Abed, L. Wenyin, V. Margner. International Conference on Document Analysis and Recognition (ICDAR 2011)-Competitions overview[C]. In Proceedings of International Conference on Document Analysis and Recognition,2011:1437-1443.
    [80]D. Karatzas, S. Robles Mestre, J. Mas, F. Nourbakhsh. ICDAR 2011 Robust Reading Competition-Challenge 1:Reading text in born-digital images (Web and Email) [C]. In Proceedings of International Conference on Document Analysis and Recognition, 2011:1485-1490
    [81]A. Shahab, F. Shafait, A. Dengel. ICDAR 2011 Robust Reading Competition Challenge 2:Reading text in scene images[C]. In Proceedings of International Conference on Document Analysis and Recognition 2011:1491-1496
    [82]Xian-Sheng Hua, Liu Wenyin, Hong-Jiang Zhang. An automatic performance evaluation protocol for video text detection algorithms [J]. IEEE Transactions on Circuits and Systems for Video Technology 2004,14(4):498-507.
    [83]V.Y. Mariano, J. Min, J.H. Park, R. Kasturi, D. Mihalcik, H. Li, D. Doermann, T. Drayer. Performance evaluation of object detection algorithms[C]. In Proceedings of International Conference on Pattern Recognition,2002:965-969.
    [84]J.C. Nascimento, J.S. Marques. Performance evaluation of object detection algorithms for video surveillance[J]. IEEE Transactions on Multimedia,2006,8(4):761-774.
    [85]R. Kasturi, D. Goldgof, P. Soundararajan, V. Manohar, J. Garofolo, R. Bowers, M. Boonstra, V. Korzhova, J. Zhang. Framework for performance evaluation of face, text, and vehicle detection and tracking in video:Data, metrics, and protocol [J]. IEEE Transactions on Pattern Analysis and Machine Intelligence,2009:319-336.
    [86]J. Liang, I.T. Phillips, R.M. Haralick. Performance evaluation of document layout analysis algorithms on the UW data set[C]. In Proceedings of Proc. SPIE, Document Recognition IV,1997:149-160.
    [87]X.S. Hua, L. Wenyin, H.J. Zhang. An automatic performance evaluation protocol for video text detection algorithms[J]. IEEE Transactions on Circuits and Systems for Video Technology,2004,14(4):498-507.
    [88]Y. Ma, C. Wang, B. Xiao, R. Dai. Usage-oriented performance evaluation for text localization algorithms[C]. In Proceedings of International Conference on Document Analysis and Recognition,2007:1033-1037.
    [89]Y.F. Pan, C.L. Liu. Performance Evaluation for Text Localization Algorithms:An Empirical Study[C]. In Proceedings of Chinese Conference on Pattern Recognition, 2010:784-788.
    [90]K. Fukunaga, L. Hostetler. The estimation of the gradient of a density function, with applications in pattern recognition[J]. IEEE Transactions on Information Theory 1975, 21(1):32-40.
    [91]Y. Cheng. Mean shift, mode seeking, and clustering[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence 1995,17(8):790-799.
    [92]D. Comaniciu, P. Meer. Distribution free decomposition of multivariate data[J]. Pattern Analysis & Applications,1999,2(1):22-30.
    [93]D. Comaniciu, P. Meer. Mean shift analysis and applications[C]. In Proceedings of IEEE International Conference on Computer Vision,1999:1197-1203.
    [94]D. Comaniciu, V. Ramesh, P. Meer. Real-time tracking of non-rigid objects using mean shift[C], In Proceedings of IEEE Computer Society Conference on Computer Vision and Pattern Recognition 2000:142-149.
    [95]D. Comaniciu, V. Ramesh, P. Meer. The variable bandwidth mean shift and data-driven scale selection[C]. In Proceedings of IEEE International Conference on Computer Vision,2001:438-445.
    [96]D. Comaniciu, P. Meer. Mean shift: a robust approach toward feature space analysis[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence,2002,24(5): 603-619.
    [97]R. T. Collins. Mean-shift blob tracking through scale space[C]. In Proceedings of IEEE Conference on Computer Vision and Pattern Recognition,2003:234-240.
    [98]R.T. Collins, Y. Liu, M. Leordeanu. Online selection of discriminative tracking features[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence,2005, 27(10):1631-1643.
    [99]贾静平.图像序列中多目标跟踪技术研究[D].西安 西北工业大学,2004.
    [100]B. Georgescu, I. Shimshoni, P. Meer. Mean shift based clustering in high dimensions: a texture classification example[C]. In Proceedings of International Conference on Computer Vision 2003:456-463.
    [101]Wu Jiang, Qu Shao-Lin, Zhuo Qing, Wang Wen-Yuan. Automatic text detection in complex color image[C]. In Proceedings of International Conference on Machine Learning and Cybernetics,2002:1167-1171.
    [102]M. R. Lyu, J. Q. Song, M. Cai. A comprehensive method for multilingual video text detection, localization, and extraction [J]. IEEE Transactions on Circuits and Systems for Video Technology,2005,15(2):243-255.
    [103]S.M. Lucas, A. Panaretos, L. Sosa, A. Tang, S. Wong, R. Young. ICDAR 2003 robust reading competitions:entries, results, and future directions[J]. International Journal on Document Analysis and Recognition,2005,2(2-3):105-122.
    [104]Laurent Itti, Christof Koch, Ernst Niebur. A model of saliency-based visual attention for rapid scene analysis[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence,1998,20(11):1254-1259.
    [105]Laurent Itti, Christof Koch. Computitional modeling of visual attention[J]. Nature Reviews| Neuroscience,2001,2:1-10.
    [106]Y. Q. Hu, D. Rajan, L. T. Chia. Detection of visual attention regions in images using robust subspace analysis[J]. Journal of Visual Communication and Image Representation,2008,19(3):199-216.
    [107]C. Koch, S. Ullman. Shifts in selective visual attention:towards the underlying neural circuitry[J]. Hum Neurobiol,1985,4(4):219-227.
    [108]Laurent Itti, Christof Koch. Feature combination strategies for saliency-based vision attention systems[J]. Electronic Imaging,2001,10(1):161-169.
    [109]Laurent Itti, Christof Koch. A comparison of feature combination strategies for saliency-based visual attention systems. Proceedinga of SPIE Human Vision and Electronic Imaging, San Jose, CA,1999,3644:473-482.
    [110]L. Itti, C. Koch. A saliency-based search mechanism for overt and covert shifts of visual attention[J]. Vision Research,2000,40(10-12):1489-1506.
    [111]R.C. Gonzalez数字图像处理.电子工业出版社,2006.
    [112]T. Lindeberg. Scale-space for discrete signals[J]. IEEE Transactions on Pattern Analysis and Machine Intelligence 1990,12(3):234-254.
    [113]T. Lindeberg. Scale-space theory in computer vision. Kluwer Academic Publishers: Netherlands 1993.
    [114]T. Lindeberg. Edge detection and ridge detection with automatic scale selection[C]. In Proceedings of IEEE Computer Society Conference on Computer Vision and Pattern Recognition,1996:465-470.
    [115]T. Lindeberg. Feature detection with automatic scale selection[J]. International Journal of Computer Vision,1998,30(2):79-116.
    [116]A. Rosenfeld, M. Thurston. Edge and curve detection for visual scene analysis[J]. IEEE Transactions on Computers,1971,100(5):562-569.
    [117]J.L. Crowley. A representation for visual information[D]. Pittsburgh, Pennsylvania Carnegie-Mellon University,1981.
    [118]刘立.基于多尺度特征的图像匹配与目标定位研究[D].武汉 华中科技大学,2008
    [119]E. C. Hildreth. The detection of intensity changes by computer and biological vision systems[J]. Computer Vision, Graphics, and Image Processing,1983,22(1):1-27.
    [120]N. Otsu. A threshold selection method from gray-level histograms[J]. IEEE Transaction Systems Man Cybernetics,1979,9(1):62-66.

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