An imaging apparatus includes at least one processor to implement: a re-sizer configured to re-size an image to a predetermined size, an encoder configured to encode the re-sized image, and a frame rate controller configured to calculate an actual bit rate of the encoded image for a preset period of time, compare a user-set target bit rate with the calculated actual bit rate, adjust a frame rate of the encoded image according to a result of the comparison, and output an encoded image signal at a user-set target bit rate irrespective of a complexity of the encoded image.