Large-Range Panoramic Image Stitching Under Sea-sky Background

Panoramic image stitching technology is a kind of image processing technology that used widely.It can stitch a set of images into a panoramic image which has wide viewing angle,high resolution and contains the original scene information.The panoramic image stitching of surveillance video can solve the small viewing angle limitation of a single camera,it can provide observers with panoramic,gap-free and real-time monitoring.This thesis focuses on the theory of image stitching technology,studies the image preprocessing theory,the image registration theory and image fusion theory,and then uses the ORB algorithm to improve the classical image stitching technology based on SIFT and SURF.For the high-resolution image with obvious feature under sea-sky background,the image stitching method based on ORB algorithm has better algorithm performance in our experiments.In addition,for the low-resolution infrared video images without obvious feature under sea-sky background,the optical flow method is applied to the image stitching technology,a very simple method for calculating the image transformation matrix is proposed.Finally,a panoramic image stitching method based on optical flow method is proposed.Experiments have proved that this method can perform well for the panoramic image stitching under sea-sky background,which overcomes the shortcomings of classical image stitching method.The main research contents and contributions of this thesis are as follows:(1)The image preprocessing theory and image stitching theory are studied,including image denoising,image geometric transformation model,feature point detection algorithm,feature point registration algorithm and image fusion algorithm,the simulation tests of these algorithms are carried out in this thesis.(2)For high-resolution image with obvious feature under sea-sky background,a panoramic image stitching method based on ORB algorithm is proposed,experimental comparison is made with the classical Autostitch image stitching method.(3)For the watermark subtitles in the infrared video image,a selective median filter is proposed to remove the watermark subtitles.Finally,for the low-resolution infrared video image without obvious feature under sea-sky background,a panoramic image stitching method based on optical flow method is designed.It can be proved that the proposed algorithm can achieve good image stitching effect for the sea-sky background infrared video image in the experimental tests.And the classical image stitching algorithm unable to do the image stitching of sea-sky background infrared video.