Text line extraction from multi-skewed handwritten documents

Preprocessing for Images Captured by Cameras

“…The extracted minimum spanning trees are not considered the text-line structures yet; some criteria are further adopted to delete redundant or add additional edges to form complete text-lines. Basu et al [23] propose a water flow method to construct textlines. Hypothetical water flows from both left and right image margins to opposite image margins.…”

Text line detection in handwritten documents

“…In Ref. [15], a text line extraction technique is presented for multi-skewed document of handwritten English or Bengali text. It assumes that hypothetical water flows, from both left and right sides of the image frame, face obstruction from characters of text lines.…”

Optimization of the Anisotropic Gaussian Kernel for Text Segmentation and Parameter Extraction

“…It is an important step in document processing. Although some text line detection techniques are successful in printed documents, processing of handwritten documents has remained a key problem in optical character recognition (OCR) [1,2]. Most text line segmentation methods are based on the assumptions that distance between neighboring text lines is significant as well as that text lines are reasonably straight.…”

“…Their validity is of major importance for OCR process. Various reasons exist for appearance of multi-skewed lines in text, but two are most common [1]. Firstly, during scanning a misalignment degrees of the document made is unavoidable.…”

“…In [1] is mentioned previously proposed and accepted technique of reference line extraction based on identifying valleys of horizontal pixel density histogram. It failed due to multi skewed text lines.…”