Failed to stitch two images vertically

[nizihan]

Hi, thanks for your nice work. But I have same problem when I stitch two images vertically. The two images have low overlap with each other, but can be stitched with opencv-image-stitch-lib, I adjust the config but still fail to stitch, could you tell me how to improve the config to stitch the vertical images? Thank U ~
The original images are shown below:


the stitch result is shown as below: