A method and system for generating a fusion image. The method may include obtaining a first image and a second image of a same scene. Pixels of at least a part of the first image may correspond to pixels of at least a part of the second image. The method may include generating, based on the first image, a first low-frequency image corresponding to a low-frequency component of the first image, the first low-frequency image including a plurality of first pixels. The method may include generating, based on the second image, a first high-frequency image corresponding to a high-frequency component of the second image, the first high-frequency image including a plurality of second pixels, the plurality of second pixels corresponding to the plurality of first pixels. The method may include determining, based on the first low-frequency image and the first high-frequency image, a featuring region in the first high-frequency image, wherein the featuring region and a region of the first image that corresponds to the featuring region have different luminance transition trends. The method may further include correcting the second pixels in the featuring region based at least in part on the first low-frequency image. And the method may also include generating a fusion image based at least in part on the first low-frequency image, and the first high-frequency image.