1. A monitoring camera comprising: a camera configured to laterally rotate and photograph an object at different times to generate a plurality of images; and a processor configured to generate a plurality of crop images by cropping overlapping portions of the plurality of images generated by the camera, and generate a 3-dimensional (3D) image by composing the plurality of crop images; wherein the 3D image includes depth information of the object, the depth information being obtained based on a distance between positions of the object in the overlapping portions of the at least two images, and wherein each crop image is generated by cropping only overlapping portions of a first image and a second image of the plurality of images, the first image and the second image being not immediately adjacent to each other among the plurality of images.