1. A method for controlling an operation in an electronic device including a photographing unit, comprising: comparing frame data between a current frame and one or more previous frames generated from the photographing unit, wherein the frame data includes contour lines, chroma, and colors; determining a movement trace of a subject included in the current frame and the one or more previous frames, based on a result of the comparing; and determining the movement trace as a gesture of the subject, wherein the gesture is for controlling the photographing unit; and executing an operation corresponding to the gesture, wherein executing the operation corresponding to the gesture comprises: if the operation corresponding to the gesture is a zoom-in operation, determining whether the gesture is at least partially outside of an angle of view of the photographing unit; and if the gesture is at least partially outside of the angle of view of the photographing unit, controlling the photographing unit to perform the zoom-in operation up to a pre-stored threshold magnification.