(JS) grabCut to findContours understanding masking

[anthony]

@Alejandro_Silvestri
Thank you very much that was the ticket

trick was to set values 2 → 0 eg:

  for (let i = 0; i < src.rows; i++) {
      for (let j = 0; j < src.cols; j++) {
          if (mask.ucharPtr(i, j)[0] == 2) {
            mask.ucharPtr(i, j)[0] = 0
          }
      }
  }