PROBLEM TO BE SOLVED: To make it possible to automatically generate a forest phase segment map from an aerial photograph etc. with high accuracy.SOLUTION: A forest phase analyzer comprises: a statistic distribution creation unit 26 a teacher data determination unit 28 and a forest phase segment map creation unit 30. The statistic distribution creation unit 26 sets an attention region in an original image which is obtained by photographing a target region from the sky at a second period corresponding to each forest phase region of the target region including the forest in an existing forest phase segment map at a first period so that statistic distribution of characteristic information with respect to the image extracted by a prescribed element region in an attention region of each forest phase is obtained. The teacher data determination unit 28 determines, when non-change region where the forest phase is not changed from the first period in each attention region occupies the greater part of the attention region, the teacher data with respect to the characteristic information of the forest phase corresponding to the non-change region is determined based on the statistic distribution of the attention region. The forest phase segment map creation unit 30 determines the forest phase in each element region of the original image on the basis of the determined teacher data of each forest phase to create the forest phase segment map for the second period.COPYRIGHT: (C)2015,JPO&INPIT【課題】航空写真等から林相区分図を高精度で自動的に生成することを可能とする。【解決手段】統計分布作成部26は森林を含む対象地域の第1の時期における既知の林相区分図での各林相の領域に対応して、対象地域を第2の時期に上空から撮影した原画像に注目領域を設定し、各林相の注目領域にて所定の要素領域ごとに抽出される画像の特徴情報について統計分布を求める。教師データ決定部28は各注目領域において第1の時期との間で林相が変わらない無変化領域が大半を占めるという条件の下で、当該注目領域における統計分布に基づいて当該無変化領域に対応する林相の特徴情報に関する教師データを決定する。林相区分図生成部30は各林相について決定された教師データにより原画像の各要素領域における林相を判別し、第2の時期における林相区分図を生成する。【選択図】図1