The present invention discloses a multimedia device for processing a video signal and control method thereof. According to an embodiment of the present invention, the multimedia device includes a controller configured to perform tone mapping, a dynamic contrast function, and a local contrast function. The controller performs the tone mapping not only on an HDR video signal but also on an SDR video signal. When performing the tone mapping on the SDR video signal, the controller amplifies only an intermediate-gradient region without adjusting low-gradient and high-gradient regions. When performing the dynamic contrast function, the controller only an intermediate-gradient region of the video signal without adjusting low-gradient and high-gradient regions. When performing the local contrast function, the controller divides the video signal into blocks, calculates an APL value of each block, and then applies a linear curve based on the APL value.