EFFICIENT EXTRACTION METHOD OF THE CHANGE OF BUILDINGS FOR FIXED PROPERTY INVESTIGATION

Abstract. In order to appraise fixed property, local governments in Japan annually investigate taxable buildings on January 1, but the efficiency of the investigation is an issue. With this context, change extraction methods of buildings have been studied using various data. However, labor and time optimization for change extraction methods remains an issue. With this in mind, the authors have concentrated on developing a change extraction method for buildings that uses only photomaps of two separate times. This paper describes the extraction method using color and texture, which can be obtained from photomaps. In order to evaluate effectiveness, the proposed method was investigated using photomaps of two separate times on various locations. It was confirmed that the proposed method extracted the changed buildings. It was also verified that the change of buildings cannot be extracted by color information only; rather, the change extraction of buildings was accomplished by using both color and texture. It should be noted that all changed buildings include extracted regions so that the change extraction of buildings is effectively performed without oversights. The proposed method could extract all changed buildings. In conclusion, the proposed method can reduce over-extraction of changed buildings by intensively visually checking extracted regions that have changes in color or texture rather than by visually checking all regions of photomaps. It is concluded that the proposed method has the ability to effectively extract changed buildings by using only photomaps.