An image capturing device, image capturing system, and image processing method, each of which: obtains a video image of an object; converts a wide-angle video image to generate a low-definition, wide-angle image; applies projection transformation to a part of the wide-angle video image to generate a high-definition, narrow-angle video image in different projection; combines each frame of the low-definition, wide-angle video image and a corresponding frame of the high-definition, narrow-angle video image, into one frame data while reducing a resolution of each video image, to generate a combined video image; transmits the combined video image for display at a communication terminal; in response to a request from the communication terminal, applies projection transformation to a part of a frame of the wide-angle video image to generate an ultra-high-definition, narrow-angle still image in different projection; and transmits the ultra-high-definition, narrow-angle still image for display at the communication terminal.