Watson Studio Pillow Documentation https://opencv-python-tutroals.readthedocs.io/en/latest/py_tutorials/py_imgproc/py_houghlines/py_houghlines.html https://opencv-python-tutroals.readthedocs.io/en/latest/py_tutorials/py_imgproc/py_thresholding/py_thresholding.html https://ibm.quip.com/1gFBAb4F6erz/Sudoku-Image-Recognition-1