Text string extraction from images of colour-printed documents

Given the mass of printed documents today, an automated entry system is highly desirable. Many techniques focusing on processing monochrome documents have been proposed in the past years but few techniques have been proposed for dealing with colour-printed documents. The authors discuss the processing of colour-printed documents in 24-bit true colour images and propose an approach for extracting text strings from them. Due to the very large amount of data in a 24-bit true colour image, processing is usually very time consuming. To reduce the computational complexity and thus speed up processing, the original colour image is first transformed into a binary image of edge representation for page segmentation. Then a new method is used to identify the text blocks. Finally, all the identified text blocks are transformed into white-background/black-text binary images for an OCR system. The proposed approach was implemented and tested on a Pentium/90 PC and experimental results have demonstrated its feasibility.