A method, medium, and system generating a depth map of a video image are provided. The depth map generating method extracts the ground of a video image other than an object from the video image, classifies the video image as a long shot image or a non-long shot image based on a distribution value of the extracted ground, calculates a depth value gradually varied along a predetermined direction of the extracted ground when the video image corresponds to the long shot image and calculates a depth value based on the object when the video image corresponds to the non-long shot image. Accordingly, a sense of space and perspective can be effectively given to even a long shot image in which the ground occupies a large part of the image and a stereoscopic image recognizable by a viewer can be generated even if rapid object change is made between scenes in a video image.