Removing text without removing the wall behind it: EAST quads to an inpaint mask

You want to wipe a sign off a wall in a video. A subtitle, a watermark, a logo painted on brick. The hard part is not finding the text. The hard part is removing only the text and leaving the brick alone. Mask one pixel too wide and the inpainter starts inventing wall where there was wall already, and now the patch looks worse than the text did. So the whole job comes down to one question: how tight is the mask. This is a walkthrough of how Wunjo Make builds that mask, straight from the code in…