Assessment of image registration for Pressure Sensitive Paint (PSP) was performed. A 16bit camera and LED lamp were used with Uni-FIB paint (ISSI). Because of model displacement and deformation at `wind-on`, a large error of the pressure ratio was induced between `wind-on` and `wind-off` images. To correct the error, many kinds of image registrations were tested. At first, control points were marked on the model surface to find the coefficients of polynomial transform functions between the `wind-off` and `wind-on` images. The 2nd-order polynomial function was sufficient for representing the model displacement and deformation. An automatic detection scheme was introduced to find the exact coordinates of the control points. The present automatic detection algorithm showed more accurate and user-friendly than the manual detection algorithm. Since the coordinates of transformed pixel were not integer, five interpolation methods were applied to get the exact pixel intensity after transforming the `wind-on` image. Among these methods, the cubic convolution interpolation scheme gave the best result. The comparison between 8bit and 16bit camera was also examined.
