Methods and systems for image combination

A method for image combination implemented on a machine having one or more processors and one or more storage devices, the method comprising:

• obtaining a first image and a second image of a same scene, the first image being captured by an image sensor using a first exposure time, the second image being captured by the image sensor using a second exposure time that is shorter than the first exposure time;
• dividing the first image into a plurality of first image blocks;
• dividing the second image into a plurality of second image blocks, each of the plurality of second image blocks corresponding to one of the plurality of first image blocks;
• for each of the plurality of first image blocks, determining a first block weight of the first image block based on edge information of the first image block and determining a second block weight of the first image block based on overall information of the first image block;
• for each of the plurality of second image blocks, determining a third block weight of the second image block based on overall information of the second image block;
• determining an exposure gain ratio based on the second block weights of the plurality of first image blocks and the third block weights of the plurality of second image blocks;
• determining a first combination weight for each of the plurality of first image blocks and a second combination weight for the corresponding second image block based on the first block weight of the first image block, the third block weight of the corresponding second image block;
• and the exposure gain ratio, a sum of the first combination weight of the first image block and the second combination weight of the corresponding second image block being a fixed value;
• and
• generating a third image by combining the first image and the second image based on the first combination weights of the plurality of first image blocks and the second combination weights of the plurality of second image blocks.

A non-transitory computer readable medium, comprising at least one set of instructions for image combination, wherein when executed by one or more processors of a computing device, the at least one set of instructions causes the computing device to perform a method, the method comprising:

• obtaining a first image and a second image of a same scene, the first image being captured by an image sensor using a first exposure time, the second image being captured by the image sensor using a second exposure time that is shorter than the first exposure time;
• dividing the first image into a plurality of first image blocks;
• dividing the second image into a plurality of second image blocks, each of the plurality of second image blocks corresponding to one of the plurality of first image blocks;
• for each of the plurality of first image blocks, determining a first block weight of the first image block based on edge information of the first image block and determining a second block weight of the first image block based on overall information of the first image block;
• for each of the plurality of second image blocks, determining a third block weight of the second image block based on overall information of the second image block;
• determining an exposure gain ratio based on the second block weights of the plurality of first image blocks and the third block weights of the plurality of second image blocks;
• determining a first combination weight for each of the plurality of first image blocks and a second combination weight for the corresponding second image block based on the first block weight of the first image block, the third block weight of the corresponding second image block, and the exposure gain ratio, a sum of the first combination weight of the first image block and the second combination weight of the corresponding second image block being a fixed value;
• and
• generating a third image by combining the first image and the second image based on the first combination weights of the plurality of first image blocks and the second combination weights of the plurality of second image blocks.