本論文提出了一套能將擷取的文件影像文字校正後變成可閱讀文件的完整系統。數位相機、文件掃描器所擷取的影像在數位化時常常因為固有體積和複雜光源而造成影像扭曲。這些影響不只降低文件可讀性而且光學文字辨識的辨識效能。在這篇論文裡，我們提出了一種串聯非線性校正與線性補償校正文件的方法，僅用2D文件影像達到提高辨識率與縮短處理時間的目的。在文件校正之前先進行頁面切割[19]、文字萃取[10]的處理。首先，移除背景光源[20]之影響，使得Otsu二值化效能提升以利文件校正。第二，在移除扭曲方面使用了三次多項式的擬合方法找出最佳近似文字線進行垂直方向校正。第三，使用線性補償對單字進行水平方向校正。最後，依據建立好之文字地圖根據使用者點擊之單字或句子發音。與現有方法比較，實驗證實本系統之有效性。 This paper proposes a complete system which can be corrected captured document images into a readable file. Document images captured by camera or scanner often suffer from warping and distortions because of the bounded volumes and complex environment light source. These effects not only reduce the document readability but also the OCR recognition performance. In this paper, we propose a method to combine non-linear and linear compensation for correcting distortions of document images. Before we proceeding text rectification the page segment [19] and the text extraction [10] methods are applied as preprocessing. First, due to the broken text result of Otsu binarization, an image processing method [20] is used to remove the effect of background light. Second, the dewarping method using the cubic polynomial fitting equation is proposed to find out the optimal approximate text line for vertical direction rectification. Third, we use linear compensation for horizontal direction rectification. Finally, according to the word/sentence clicked by user the system will performing text to speech.
