1. A method of generating a high dynamic range (HDR) image corresponding to a specific scene, comprising: shooting a specific scene to generate a base image; selecting a bright area and a dark area from the base image; determining base luminance according to the base image; shooting the specific scene to generate at least a first image, wherein average luminance of a part of the first image corresponding to the bright area of the base image is less than or equal to the base luminance; shooting the specific scene to generate at least a second image, wherein average luminance of a part of the second image corresponding to the dark area of the base image is greater than or equal to the base luminance; and combining at least the first image and the second image into an HDR image corresponding to the specific scene; wherein the step of selecting the bright area and the dark area from the base image comprises: dividing the base image into a plurality of blocks; calculating average luminance of each block individually; for each base image generated and regardless of the luminance properties of the base image, selecting at least one block whose average luminance lies in a high luminance range as the bright area; and for each base image generated and regardless of the luminance properties of the base image, selecting at least one block whose average luminance lies in a low luminance range as the dark area.