Complementary Coded Apertures
Original Publication Date: 1983-Aug-01
Included in the Prior Art Database: 2005-Feb-07
Given an nxn binary mask (or coded aperture A) with decoding array G such that A*G = w G where * is the correlation operator and w G is an nxn matrix, everywhere zero except for one point with value ¯w G¯, then we define the complementary array to A to be B = U - A, where U is the nxn matrix consisting entirely of unit entries. For those arrays A with openness density >50%, the array B will have density <50%. Masks with openness >50% are rarely used in practice. However, certain classes of mask, defined algorithmically, may contain individual members with density over 50%. When this occurs, it is more attractive to employ the complementary array to A, obtained from A by converting open areas into closed areas, and vice versa.