The technology of automatic pattern recognition and digital image processing, after over two decades of basic research, is now appearing in important applications in biology and medicine as weIl as industrial, military and aerospace systems. In response to a suggestion from Mr. Norman Caplan, ·the Program Director for Automation, Bioengineering and Sensing at the United States National Science Foundation, the authors of this book organized the first Uni ted States-France Seminar on Biomedical Image Processing. The seminar met at the Hotel Beau Site, St. Pierre de Chartreuse, France on May 27-31, 1980. This book contains most of the papers presented at this seminar, as weIl as two papers (by Bisconte et al. and by Ploem ~ al.) discussed at the seminar but not appearing on the program. We view the subject matter of this seminar as a confluence amon~ three broad scientific and engineering disciplines: 1) biology and medicine, 2) imaging and optics, and 3) computer science and computer engineering. The seminar had three objectives: 1) to discuss the state of the art of biomedical image processing with emphasis on four themes: microscopic image analysis, radiological image analysis, tomography, and image processing technology; 2) to place values on directions for future research so as to give guidance to agencies supporting such research; and 3) to explore and encourage various areas of cooperative research between French and Uni ted States scientists within the field of Biomedical Image Processing.