In the recent time, computational techniques and algorithms have been successfully adapted to solve a lot of problems in image processing and pattern recognition. However potentialities of the computational techniques and algorithms have not been investigated adequately. Hence, we thought of writing a book on Computational Techniques and Algorithms in Handling Image Processing and Pattern Recognition. We believe that team work will alone yield a good material in this hottest area. Consequently we collected chapters from 28 academic teams working in various sub-fields of image processing from various countries such as USA, UK, Mexico, Poland, Jordan, India, Pakistan and Korea. The materials presented in this book are reviewed by 35 reviewers and finally we have accepted 17 chapters out of 28 chapters received based on the recommendations and comments from the reviewers. The reader is provided with a concise list of references at the end of each chapter. These 17 chapters are divided into four parts namely; Part A- PATTERN RECOGNITION; Part B- IMAGE IMPROVEMENT; Part C- IMAGE COMPRESSION and Part D- IMAGE WATERMARKING AND STEGANOGRAPHY.