Dan Shmuel Chevion

High efficiency, multiplication free approximation of arithmetic coding

An alternative procedure for reducing the computational complexity, which is applicable to both binary and multialphabet arithmetic coding, is described and its performance analysed with respect to the small increase in code length.<<ETX>>

Hybrid Approach to Adaptive OCR for Historical Books

Optical character recognition (OCR) technology is widely used to convert scanned documents to text. However, historical books still remain a challenge for state-of-the-art OCR engines. This work proposes a new approach to the OCR of large bodies of text by creating an adaptive mechanism that adjusts itself to each text being processed. This approach provides significant improvements to the OCR results achieved. Our approach uses a modified hierarchical optical flow with a second-order regularization term to compare each new character with the set of super-symbols (character templates) by using its distance maps. The classification process is based on a hybrid approach combining measures of geometrical differences (spatial domain) and distortion gradients (feature domain).

Image Processing Based Approach for Retrieving Data from a Seismic Section in Bitmap Format

A new method for retrieving seismic data from a seismic section provided in a bitmap format is described. The method is based on image processing techniques and includes creating a grey level image of a seismic section, processing the grey level image (by integration, filtering, etc.) and then reconstructing digitized values of individual seismic traces_ from the resulting image, thus ending with the data in standard SEG-Y format