PROBLEM TO BE SOLVED: To provide an image processor capable of identifying a function index of a blood vessel with low invasion and with a high speed, and to provide an image processing method, and program.SOLUTION: According to an embodiment, an image processor includes an acquisition part, a calculation part, and an identification part. The acquisition part acquires a time series of images including a blood vessel of a subject, and correlation information showing a correlation between a physical index of the blood vessel and a function index of the blood vessel about a blood circulation state of the blood vessel. The calculation part calculates a blood vessel form index in time series showing a form of the blood vessel of the subject on the basis of the time series of images. The identification part identifies the function index of the blood vessel of the subject from the physical index of the blood vessel of the subject obtained from the blood vessel form index on the basis of the correlation information.【課題】低侵襲で且つ高速に血管の機能指標を同定することができる画像処理装置、画像処理方法、及びプログラムを提供すること。【解決手段】実施形態に係る画像処理装置は、取得部と、算出部と、同定部とを備える。取得部は、被検体の血管を含む時系列の画像と、血管の物理指標と血管血行状態に関する血管の機能指標との相関関係を示す相関情報と、を取得する。算出部は、前記時系列の画像に基づいて、前記被検体の血管の形態を示す時系列の血管形態指標を算出する。同定部は、前記相関情報に基づいて、前記血管形態指標により得られる前記被検体の血管の物理指標から、前記被検体の血管の機能指標を同定する。【選択図】図１
