Problem to be solved: to provide a technique capable of measuring the size of the object to be accurately measured while maintaining the operation of the conventional endoscope while suppressing the cost at the time of introduction of the endoscope system.Solution: a distance acquisition means for acquiring an object distance which is a distance between an endoscope and an object from the intensity of the reflected light of light illuminated from an object, a scale generating means for generating a scale as an index of the object size based on the object distance, and the scale and object generated by the scale generating means An image synthesizing means for synthesizing the image with the image, and a display means for displaying the scale of the object synthesized by the image synthesizing means and the image of the object, and the distance acquisition means reflects the light in the mucosa of the human cavityA storage portion storing a table storing the relationship between the intensity of the reflected light and the object distance based on the rate, and a acquiring section for acquiring the object distance corresponding to the intensity of the reflected light of the light irradiated to the object from the table.Selection diagram【課題】内視鏡システム導入時のコストを抑え、従来の内視鏡の操作を維持しつつ、より精度よく撮像対象物の大きさを測定可能とする技術を提供する。【解決手段】対象物に照射した光の反射光の強度から内視鏡と対象物の間の距離である対象間距離を取得する距離取得手段と、対象間距離に基づいて、対象物の大きさの指標となる目盛を生成する目盛生成手段と、目盛生成手段により生成された目盛と対象物の画像とを合成する画像合成手段と、画像合成手段によって合成された前記目盛と前記対象物の画像を表示する表示手段と、を備え、距離取得手段は、人の口腔内の粘膜における光の反射率に基づく、反射光の強度と対象間距離との関係を格納したテーブルを記憶した記憶部と、テーブルから、対象物に照射した光の反射光の強度に対応する対象間距離を取得する取得部と、を有する。【選択図】図13
