US Patent 7593596 Phase unwrapping method, program, and interference measurement apparatus

A candidate pixel generating unit searches a path-undetermined adjacent pixel j which is adjacent around a parent pixel i, and, with respect to the searched adjacent pixel j, generates a candidate pixel having data {j(i,|Wij|)} in which the parent pixel i and magnitude |Wij| of a phase difference Wij in which phase skip between the pixels is corrected are combined. The registration control unit registers the pixel to a heap having a function of ordering the registration order, and order the pixel, if the weight |Wij| is equal to or more than a predetermined threshold value TH; and registers the pixel to a queue not having the function of ordering the registration order if it is less than the threshold value TH. A path determination unit prioritizes the queue to retrieve and eliminate one candidate pixel, and determines a path between the eliminated candidate pixel and the parent pixel.