The invention provides an image capture device and an image processing method thereof. The image processing method includes the following steps. First, an image signal source is received by a receiving unit, wherein the image signal source has a plurality of image frames and plurality corresponding image information or plurality of corresponding variable refresh rate (VRR) related information. Next, it is determined whether the image signal source is a VRR signal, and a determination result is generated. A time stamp of each image frame is calculated according to the VRR-related information if the determination result is positive, wherein the time stamps correspond to a dynamic frame interval respectively. Next, the image frames are respectively converted into a corresponding output packet. Finally, the output packets are respectively integrated with their respective time stamps to generate a dynamic frame interval output packet.