Method for correcting rolling shutter effect and image processing device using the same

An image processing device, comprising:

• a memory, storing a plurality of instructions;
• and
• a processor, coupled to the memory, configured to execute the instructions to execute a plurality of steps:
• obtaining a plurality of feature point pairs in a plurality of images of a video, wherein each of the feature point pairs corresponds to a motion vector, and the video is captured by an image capturing unit;
• obtaining a plurality of sampling points between two consecutive images of the images in time, wherein each of the sampling points corresponds to a row location;
• setting at least one moving velocity and at least one angular velocity of the image capturing unit at each of the sampling points as a plurality of variables;
• obtaining a plurality of estimating motion vectors of the feature point pairs according to the variables, a focal length of the image capturing unit and the row locations where the feature point pairs are located;
• executing an optimization algorithm according to a difference between the motion vectors and the estimating motion vectors, so as to calculate the at least one moving velocity and the at least one angular velocity corresponding to the variables;
• and
• varying locations of a plurality of pixels in one of the images according to the at least one moving velocity and the at least one angular velocity corresponding to the variables, so as to generate a first corrected image.