Image distortion correction for wireless capsule endoscope

The images captured by wireless capsule endoscope might have nonlinear spatial distortion, which makes accurate medical examination difficult. So it is a prerequisite to have this distortion corrected. Typically, the correction uses a calibration pattern, which might be a chess board, dot, grid, or circle pattern. Based on this pattern, enough characteristic samples can be extracted accurately and conveniently, and mathematic model can be built for the distortion in the captured image with respect to the original calibration pattern. Then the correction parameters, including image centers and mapping polynomials, could be found to realize the correction. If the model is too complicated to be accurately built, correction using neural network is a good choice, since it does not rely on the mathematic model of the distortion.