1. An apparatus to compress a video comprising pixels, the apparatus comprising: a region of interest (ROI) estimating part to estimate ROI information associated with a first ROI in the video; a parameter allocating part to allocate a first compression parameter to the first ROI in the video based on the ROI information; and a compression part to compress the video by applying the first compression parameter allocated to the first ROI, wherein: the ROI information comprises at least one of: a probability that each macroblock of the video belongs to the first ROI; and information associated with regions of the image having a probability of belonging to the first ROI that is greater than a predetermined threshold; the first compression parameter comprises at least one of a bit rate and an adjustable parameter provided by a video standard associated with the video; and the compression part comprises: a pre-treatment part configured to perform a pre-treatment by changing a resolution of the whole video; and an encoder configured to compress the video.