A method for image combination may include obtaining a first image and a second image; dividing the first image into a plurality of first image blocks and dividing the second image into a plurality of second image blocks; for each of the plurality of first image blocks, determining a first block weight based on edge information of the first image block and determining a second block weight based on overall information of the first image block; for each of the plurality of second image blocks, determining a third block weight based on overall information of the second image block; determining an exposure gain ratio based on the second block weights and the third block weights; determining a first combination weight and a second combination weight based on the exposure gain ratio; generating a third image based on the first combination weights and the second combination weights.