Surround view bird's eye stitching

So I am trying to generate a bird’s eye view for my college graduation project and I’ve successfully done:

  1. calibrate fish eye cameras and undistort them (I am using four cameras, right, left, front, back)
  2. use preceptive transform to generate a bird’s eye view for each of the four frames

and now I need to stitch them together, anyone has any idea how to implement this ? I am using python and OpenCv. I tried using the stitcher class but it did not work:

stitcher = cv2.Stitcher.create(cv2.Stitcher_PANORAMA)
(status,result) = stitcher.stitch(warped) # warped is a list containing 4 images 
if (status == cv2.STITCHER_OK):
    print('Panorama Generated')
else:
    print('Panorama Generation Unsuccessful')

it’s always Unsuccessful, the status is 1

flickr url : https://flic.kr/ps/3Vfxsx

please provide data (pics or …).

related: python - OpenCV bird's eye view stitching - Stack Overflow

thanks, i uploaded them to flickr and edited the post

some of those top-down pictures don’t look exactly top-down. you should figure out what went wrong there.

for stitching you need considerable overlap, especially in synthetic images that contain very few usable features for feature matching (stitching uses that).

calibrating this is tricky and definitely can’t be explained in a forum post. please do literature research, look at existing solutions. there are books on “multi view geometry”. you are not expected to reinvent this on your own.

thank you ! after getting the top-down views correctly i just use the stitcher class ?