1. A method executed by a computer system that stitches satellite images into a wide-angle image, the method comprising: dividing, by the computer system, each of the satellite images into plural subimages; determining, by the computer system, whether the subimages include an overlap area that overlaps with adjacent subimages; obtaining, by the computer system, cropped subimages by removing the overlap area from the subimages; generating, by the computer system, preprocessed satellite images each including the cropped subimages; selecting, by the computer system, a reference image and a target image from the preprocessed satellite images, the reference image and the target image sharing an overlap region; determining, by the computer system and based on a feature matching algorithm, plural correspondent pairs in the overlap region, each of the correspondent pairs including a reference location in the reference image and a target location in the target image; obtaining, by the computer system and based on coordinates of the correspondent pairs, a transformation matrix by a least-squares algorithm; obtaining, by the computer system, calibrated coordinates for each pixel of the target image by applying the transformation matrix; stitching, by the computer system and based on the calibrated coordinates of the target image, the target images into the wide-angle image.