Transparent structure internal flow field image distortion correction system and method based on affine and B-spline grid transformation

The invention provides a transparent structure internal flow field image distortion correction system and method based on affine and B-spline grid transformation. The system comprises calibration paper, a structure outer sleeve box body, a PIV system and a post-processing algorithm. The calibration paper is arranged in the structure and needs to be fully distributed on the plane to be measured, so that a distorted image can be directly observed; a structure to be detected is covered with a watertight box body sleeved with the structure, the box body is filled with a solution in the structure, an observation window observed from the outside of the box body is a plane, and the observed image distortion condition is basically corrected; the PIV system comprises two high-speed cameras, a laser, a synchronizer and a computer; the polynomial mapping relation of image points before and after distortion is obtained through post-processing software, the mapping relation is reversely applied to the flowing image in the