Improving biomedical image quality with computers
Robert H. Selzer · NASA STI Repository (National Aeronautics and Space Administration) · 1968
The analysis of pictorial data in th e biomedical fi elds has increased sufficiently in the p ast few years to warrant the use of computers to process this data.A description of image processing research conducted at the Jet Propulsion Laboratory, particularly in the area of image enhancement, is contained in this p aper.Frequency-response methods, which allow computer p rocessin g techniques to be directly related to the imaging system and to the image subj ect, are discussed.The most important enhancement technique, two-dimensional digital filtering, is described and illustrated with numerical examples .Exampl es of b efore-and-after computer-processed pictures are shown which illustrate low-p ass, high-pass, high-frequency restoration , feature-selective and nonlinear filters.Sub traction techniques are also discussed and an exa mple is given of a computerized filmmeasurement procedure that requires preprocessin g of the image by filterin g techn iques.This applica tion in volves measurement of the width of trab ecular bone shadows from x-ray film .