House change judging method and device using color gradation and altitude values of image polygon data

A house change judging method for judging a change of a house in a data acquisition region based on new data and old data concerning two periods, which have been aerially acquired, comprising:

• setting predetermined meshes in a judgment target region in the new data and the old data concerning two periods;
• setting, after the setting of the predetermined meshes, a mesh altitude judgment value with an altitude value difference as a standard to each of the predetermined meshes;
• and
• judging whether a house change has occurred in a judgment region based on the mesh altitude judgment value, wherein
• the mesh altitude judgment value is given as a linear combination value of a difference in altitude average in a mesh between the new data and the old data and an evaluation value based on a difference in distance of an appropriate number of higher altitude points between the new data and the old data extracted in a mesh that is the same between the new data and the old data.

A house change judging device for judging a change of a house in a data acquisition region based on new data and old data concerning two periods, which have been aerially acquired, comprising:

• judgment target region extracting means for extracting as a judgment target region a predetermined region in the new data and the old data concerning the two periods by trimming with house polygon data corresponding to a predetermined region prepared in advance;
• evaluation value computing means for computing as evaluation values two kinds of difference values between the new data and the old data concerning the two periods with respect to a gradation value of color image data and an altitude value of altitude data across the entire judgment target region;
• and
• judging means for judging, based on the evaluation values, whether a house change has occurred in the judgment target region by referring to a judging table including combinations of two kinds of preset evaluation criterion values.

A house change judging device for judging a change of a house in a data acquisition region based on new data and old data concerning two periods, which have been aerially acquired, comprising:

• mesh setting means for setting predetermined meshes in a judgment target region in the new data and the old data concerning two periods;
• mesh altitude judgment value setting means for setting a mesh altitude judgment value with an altitude value difference as a standard to each of the predetermined meshes;
• and
• judging means for judging whether a house change has occurred in a judgment region based on the mesh altitude judgment value, wherein
• the mesh altitude judgment value is given as a linear combination value of a difference in altitude average in a mesh between the new data and the old data and an evaluation value based on a difference in distance of an appropriate number of higher altitude points between the new data and the old data extracted in a mesh that is the same between the new data and the old data.