Method of and apparatus for the expansion of the range of the depth of focus beyond the limit given by conventional images

摘要

A method of and apparatus for increasing the range of depth of focus when optically imaging three dimensional objects having different depth ranges corresponding to desired image levels wherein the object is focused through at a plurality of levels to produce a plurality of images. At each level, the image produced has sharp details and unfocused details. Each image is filtered with a high pass filter to suppress unfocused details and to pass sharp details. The images are then summed to produce a composite image containing only the sharp details passed by the filtering step. If desired, the filter may be selectively by-passed in order to sum unfiltered images. By utilizing the method of an apparatus for practicing the instant invention more meaningful visual displays of three-dimensional objects are obtained.