The rectified images are built up row by row. Each row corresponds to a certain angular sector. The length along the epipolar line is preserved. Figure 7.7 clarifies these concepts. The coordinates of every epipolar line are saved in a list for later reference (i.e. transformation back to original images). The distance of the first and the last pixels are remembered for every epipolar line. This information allows a simple inverse transformation through the constructed look-up table.
Note that an upper bound for the image size is easily obtained. The height is bound by the contour of the image . The width is bound by the diagonal . Note that the image size is uniquely determined with our procedure and that it is the minimum that can be achieved without pixel compression.