To illustrate a two-dimensional cross-correlation operation, consider an input tensor with a shape of $3 \times 3$ and a kernel tensor with a shape of $2 \times 2$. The convolution window begins at the upper-left corner of the input. The input subtensor within this window and the kernel are multiplied elementwise, and the products are summed to yield a single scalar value: $0\times0+1\times1+3\times2+4\times3=19$. As the window slides across the input tensor from left to right and top to bottom, this process is repeated. The resulting output tensor has a shape of $2 \times 2$ and contains the four derived scalar values: $19$, $25$, $37$, and $43$.