Abstract: Key points are very few when extracted by the SIFT algorithm directly and mismatch points are much more during the image matching of the next step from blur image. We propose a matching algorithm based on SIFT feature. Firstly, we use the Laplacian operator to sharpen the blurred image in order to highlight the edge, and then extract the key points by the SIFT algorithm. Lastly, we use the bidirectional matching algorithm to match image. The experimental results show that the number of matched points by the improved algorithm has more points than the way of using SIFT algorithm directly and the results of matching are better.

Key words: SIFT algorithm, Laplacian operator, image sharpening, bidirectional matching algorithm