Method of digital removal of micro-defects in photographs

摘要

Photographic development and copying processes are associated with the formation of micro-defects, e.g. dust particles, fluff, patches with missing emulsion on the film layer. A method by which these micro-defects can be removed by digital image processing is given. In it, an image section which includes micro-defects is copied from a digitised image pattern. The micro-defect is then masked out by being completely enclosed by a polygon, the polygon is subjected to area filling and the image section to context-related filtering, in the case of linear micro-defects by two separate foldings, with a column operator (n x 1) and a row operator (1 x n, with 3 < n < 9) and application of a median filtering. For area micro-defects, the filtering is done using an n x n-sized operator, which arithmetically implements a maximum value filter. The filtered image section is overlaid with the area polygon, and an image mask using the area polygon is produced as a template, which is inserted in the image section instead of the micro-defect (Fig. 13). <IMAGE>