The former application generates two grids of displacements. The GridBasedImageResampling allows to resample the two input images in the epipolar geometry using these grids. These grids are intermediary results not really useful on their own in most cases. This second step only consists in applying the transformation and resample both images. This application can obviously be used in lot of other contexts.
The two commands to generate epipolar images are:
As you can see, we set sizex and sizey parameters using output values given by the StereoRectificationGridGenerator application to set the size of the output epipolar images.
We obtain two images in epipolar geometry, as shown in figure 4.17. Note that the application allows to resample only a part of the image using the -out.ulx and -out.uly parameters.