Patent ID: 7027653

Claim:
A variation detecting apparatus for detecting variations in ground objects in one and the same area between a line drawing map describing profile lines of said ground objects or an image obtained by picking up said ground objects from above (hereinafter referred to as “reference line drawing/image”) and an image obtained by picking up said ground objects in the same area from above later on (hereinafter referred to as “target image”), comprising: means for collating said reference line drawing/image with said target image so as to obtain variation indexes indicating whether there are variations or not in said ground objects respectively; means for displaying ground objects which can be judged to have variations or ground objects which cannot be judged as to whether there are variations or not on the basis of said variation indexes, for visual confirmation for variation in a display mode in which an area of said reference line drawing/image including said ground objects and an area of said target image including said ground objects can be compared with each other; and means for storing ground objects judged to have variations by said visual confirmation for variation and ground objects which do not have to be subjected to said visual confirmation for variation but which can be judged to have variations on the basis of said variation indexes, as ground objects whose confirmation results are regarded as variation present.