As i know, Structure Tensor is:

How i compute $ I_x^2, I_y^2, I_xI_y$ . I used **Hadamard product** for compute $ I_x^2, I_y^2, I_xI_y$ . But if i use **Hadamard product** i will get $ det(M) = 0$ . I’m stuck in here for too long. Can anyone explain for me?. Thank you.