Skew angle detection of bangla script using radon transform

Abstract

Skew angle detection and correction an integral part of any OCR system. Without proper skew correction, the performance of an OCR will simply not be acceptable for most scanned images. We propose an innovative method for skew angle detection and correction for Bangla scripts using the Radon Transform. The basic idea is to identify the upper envelope by detecting the headline that accompanies most of the letters in the Bangla script, and then apply the Radon Transform to this upper envelope to get the skew angle. Once the angle is known, the correction is quite trivial to perform. While the current implementation handles only a single skew angle per text image, it can be extended to handle multiple skew angles by partitioning the document image.