1. A pedestrian behavior predicting device comprising: a processor including hardware; and a storage unit including memory storing instructions executable by the processor and for storing shape information of a pedestrian, wherein the processor executes the instructions stored in the memory to cause the pedestrian behavior predicting device to: detect a pedestrian from an imaged image; acquired at a current time extract a partial image including the detected pedestrian from the imaged image; acquire shape information of the pedestrian from the extracted partial image, the shape information of the pedestrian including at least one of a luminance of the partial image, an edge of the partial image, and a color of the partial image; accumulate the acquired shape information of the pedestrian in the storage unit; detect a change in movement of the pedestrian by comparing shape information of the pedestrian from an image captured a predetermined time before the current time and the acquired shape information of the pedestrian using the accumulated shape information of the pedestrian, store first images and pieces of discontinuous movement estimating information in the storage unit such that each first image is associated with each piece of discontinuous movement estimating information, the first image being an image that was acquired at a time when a first change in the movement of the pedestrian is detected, the piece of discontinuous movement estimating information being information indicating a discontinuous movement of the pedestrian that occurs following the first change in the movement of the pedestrian; wherein when a second change in the movement of the pedestrian is detected, search, from the first images stored in the storage unit, a first image corresponding to a second image when the second change in the movement of the pedestrian is detected; acquire a piece of discontinuous movement estimating information associated with the searched first image; and predict a behavior of the pedestrian using the acquired piece of discontinuous movement estimating information.