The objective of the present invention is to provide an image processing device, an endoscope system, and an image processing method, allowing images to be acquired with a plurality of observation lights as needed, while suppressing any effects on observation by a user. The image processing device according to a first mode of the present invention acquires sequentially and displays as a moving image first images yielded with a first observation light, until static image acquisition instructions are received, if the static image acquisition instructions have been received, acquires as static images first and second images yielded with the first and a second observation lights, and after the acquisitions of the static images are finished, returns to the acquisition and display of the moving image from the first images yielded with the first observation light. Consequently, while continuing observation via the first images, the user can, as needed (for instance, as instructed by the user, or with a timing at which the acquisition of a static image is needed, such as when a region-of-interest has been detected), acquire static images with the first and the second observation lights, and, along with the observation, perform classification of the photographed bodies.L'objectif de la présente invention concerne un dispositif de traitement d'image, un système d'endoscope et un procédé de traitement d'image, permettant l'acquisition d'images à l'aide d'une pluralité de lumières d'observation selon les besoins, tout en supprimant tout effet sur l'observation par un utilisateur. Le dispositif de traitement d'image selon un premier mode de la présente invention acquiert séquentiellement et affiche en tant qu'image animée des premières images obtenues à l'aide d'une première lumière d'observation, jusqu'à ce que des instructions d'acquisition d'image statique soient reçues, si les instructions d'acquisition d'image statique ont été reçues, il acquiert en tant qu'images statiques
