Grid Correction

Method

The grid correction application uses the sparse matches computed by the sparse matching application, to correct the initial epipolar grid.

We follow the following steps:

• Interpolate the sparse matches to generate an imperfect epipolar grid, and where whe should land in sensor geometry.

• Simulate perfect matches: find where it should have landed if we had perfect matches.

• Compute residuals: difference between raw and perfect sensor position.

• We estimate a correction model, with least square fit.=: polynomial coefficients are estimated

• We apply the correction model to the initial epipolar grid, to get a corrected epipolar grid.

Limits of the method

We assume that the error varies smoothly across the image, which is not always the case, for instance with vibrations. The correction model is then not adapted to correct such errors.