Automatic inspection of solar panels based on Images stitching technique

Solar panels outer surface inspection is among the most challenging tasks which burden the solar plants supervisors. An automatic inspection based on image processing ensured by robots seems beneficial. In our approach, a robot equipped with an HD camera and a processing unit browses a set of solar panels (placed alongside). Afterward, the robot captures a series of successive images containing a set of targeted panels. Thereafter, the system generates a panoramic image of the panels which helps the said supervisors to check up the solar panels outer state i.e. (present of: dust, breaking, cracks,…) The proposed system is able to operate as an embedded system (ensured by Raspberry Pi card). It consists of two main stages: (1) images indexation and (2) Images stitching. As regards to the first stage, a series of solar panels images are captured successively and each of them is watermarked by a robust index, based on the convolutional encoding method and on the DCT blocks watermarking technique. Thereafter, the images undergo a brightness compensation as to obtain an accurate panoramic image. As for the second stage, the system starts by extracting the interest points (based on the SURF algorithm) of each captured image. Afterwards, the system implements a combination of Homography and RANSAC algorithm as to remove the mismatching points. And finally, each image undergoes a geometrical transformation according to the remaining matching points and subsequently the resulting images are stitched respectively as to obtain a panoramic image.